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Sample records for herbivore-induced esp-independent nitrile

  1. Nitrile Metabolizing Yeasts

    Science.gov (United States)

    Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

    Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

  2. Where do herbivore-induced plant volatiles go?

    Directory of Open Access Journals (Sweden)

    Jarmo K. Holopainen

    2013-06-01

    Full Text Available Herbivore induced plant volatiles (HIPV are specific volatile organic compounds (VOC that a plant produces in response to herbivory. Some HIPVs are only produced after damage, while others are also produced by intact plants, but in lower quantities. Among the known functions of HIPVs are within plant volatile signalling to activate systemic plant defences, the priming and activation of defences in neighbouring plants and the attraction of natural enemies of herbivores. When released into the atmosphere a plant’s control over the produced compounds ends. However, many of the HIPVs are highly reactive with atmospheric oxidants and their atmospheric life times could be relatively short, often only a few minutes. We summarise the potential ecological and atmospheric processes that involve the reaction products of HIPVs in their gaseous, liquid and solid secondary organic aerosol (SOA forms, both in the atmosphere and after deposition on plant surfaces. A potential negative feedback loop, based on the reactions forming SOA from HIPV and the associated stimulation of sun screening cloud formation is presented. This hypothesis is based on recent field surveys in the geographical areas facing greatest degree of global warming and insect outbreaks. Furthermore, we discuss how these processes could benefit the individual plant or conspecifics that originally released the HIPVs into the atmosphere. Further ecological studies should aim to elucidate the possible reasons for biosynthesis of short-lived volatile compounds to have evolved as a response to external biotic damage to plants.

  3. Herbivore-induced blueberry volatiles and intra-plant signaling.

    Science.gov (United States)

    Rodriguez-Saona, Cesar R

    2011-12-18

    Herbivore-induced plant volatiles (HIPVs) are commonly emitted from plants after herbivore attack. These HIPVs are mainly regulated by the defensive plant hormone jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA). Over the past 3 decades researchers have documented that HIPVs can repel or attract herbivores, attract the natural enemies of herbivores, and in some cases they can induce or prime plant defenses prior to herbivore attack. In a recent paper, I reported that feeding by gypsy moth caterpillars, exogenous MeJA application, and mechanical damage induce the emissions of volatiles from blueberry plants, albeit differently. In addition, blueberry branches respond to HIPVs emitted from neighboring branches of the same plant by increasing the levels of JA and resistance to herbivores (i.e., direct plant defenses), and by priming volatile emissions (i.e., indirect plant defenses). Similar findings have been reported recently for sagebrush, poplar, and lima beans. Here, I describe a push-pull method for collecting blueberry volatiles induced by herbivore (gypsy moth) feeding, exogenous MeJA application, and mechanical damage. The volatile collection unit consists of a 4 L volatile collection chamber, a 2-piece guillotine, an air delivery system that purifies incoming air, and a vacuum system connected to a trap filled with Super-Q adsorbent to collect volatiles. Volatiles collected in Super-Q traps are eluted with dichloromethane and then separated and quantified using Gas Chromatography (GC). This volatile collection method was used in my study to investigate the volatile response of undamaged branches to exposure to volatiles from herbivore-damaged branches within blueberry plants. These methods are described here. Briefly, undamaged blueberry branches are exposed to HIPVs from neighboring branches within the same plant. Using the same techniques described above, volatiles emitted from branches after exposure to HIPVs are collected and

  4. An ecogenomic analysis of herbivore-induced plant volatiles in Brassica juncea

    NARCIS (Netherlands)

    Mathur, V.; Tytgat, T.O.G.; Hordijk, C.A.; Harhangi, H.R.; Jansen, J.J.; Reddy, A.S.; Harvey, J.A.; Vet, L.E.M.; Dam, van N.M.

    2013-01-01

    Upon herbivore feeding, plants emit complex bouquets of induced volatiles that may repel insect herbivores as well as attract parasitoids or predators. Due to differences in the temporal dynamics of individual components, the composition of the herbivore-induced plant volatile (HIPV) blend changes

  5. Chemical and molecular ecology of herbivore-induced plant volatiles: proximate factors and their ultimate functions.

    Science.gov (United States)

    Arimura, Gen-Ichiro; Matsui, Kenji; Takabayashi, Junji

    2009-05-01

    In response to herbivory, plants emit specific blends of herbivore-induced plant volatiles (HIPVs). HIPVs mediate sizable arrays of interactions between plants and arthropods, microorganisms, undamaged neighboring plants or undamaged sites within the plant in various ecosystems. HIPV profiles vary according to the plant and herbivore species, and the developmental stages and conditions of the live plants and herbivores. To understand the regulatory mechanisms underling HIPV biosynthesis, the following issues are reviewed here: (i) herbivore-induced formation of plant volatile terpenoids and green leaf volatiles; (ii) initial activation of plant responses by feeding herbivores; and (iii) the downstream network of the signal transduction. To understand the ecological significance of HIPVs, we also review case studies of insect-plant and inter-/intraplant interactions mediated by HIPVs that have been documented in the field and laboratory in recent years.

  6. Insect attraction to herbivore-induced beech volatiles under different forest management regimes.

    Science.gov (United States)

    Gossner, Martin M; Weisser, Wolfgang W; Gershenzon, Jonathan; Unsicker, Sybille B

    2014-10-01

    Insect herbivore enemies such as parasitoids and predators are important in controlling herbivore pests. From agricultural systems we know that land-use intensification can negatively impact biological control as an important ecosystem service. The aim of our study was to investigate the importance of management regime for natural enemy pressure and biological control possibilities in forests dominated by European beech. We hypothesize that the volatile blend released from herbivore-infested beech trees functions as a signal, attracting parasitoids and herbivore enemies. Furthermore, we hypothesize that forest management regime influences the composition of species attracted by these herbivore-induced beech volatiles. We installed flight-interception traps next to Lymantria dispar caterpillar-infested young beech trees releasing herbivore-induced volatiles and next to non-infested control trees. Significantly more parasitoids were captured next to caterpillar-infested trees compared to non-infested controls, irrespective of forest type. However, the composition of the trophic guilds in the traps did vary in response to forest management regime. While the proportion of chewing insects was highest in non-managed forests, the proportion of sucking insects peaked in forests with low management and of parasitoids in young, highly managed, forest stands. Neither the number of naturally occurring beech saplings nor herbivory levels in the proximity of our experiment affected the abundance and diversity of parasitoids caught. Our data show that herbivore-induced beech volatiles attract herbivore enemies under field conditions. They further suggest that differences in the structural complexity of forests as a consequence of management regime only play a minor role in parasitoid activity and thus in indirect tree defense.

  7. Effect of the postfeeding interval on olfactory responses of thrips to herbivore-induced cotton plants.

    Science.gov (United States)

    Silva, Rehan; Walter, Gimme H; Wilson, Lewis J; Furlong, Michael J

    2016-12-01

    We investigated the responses of 3 thrips species, Frankliniella schultzei Trybom, F. occidentalis Pergrande, and Thrips tabaci Lindeman (Thysanoptera: Thripidae) to herbivore-damaged and undamaged cotton seedlings (Gossypium hirsutum L. [Malvales: Malvaceae]) at a range of time intervals following damage by adult Tetranychus urticae (Koch), adult T. ludeni (Zacher) (Acari: Tetranychidae) or Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae in olfactometer assays. The intensity/frequency of the response of thrips to herbivore-induced plants decreased with time and ultimately disappeared in all cases; however, the rate at which the response declined was related to the herbivore species that inflicted the damage. All 3 species of thrips were attracted to plants damaged by T. urticae for longer than they were to plants damaged by T. ludeni. The duration for which damaged plants remained attractive was also affected by the degree of damage inflicted on cotton seedlings. For example, F. schultzei was attracted to plants damaged by a higher density of two-spotted spider mites (100/plant) for much longer than to plants damaged by a lower density of these mites (50/plant). The results reinforce previous studies that demonstrate that arrangement of variables influences the responses of thrips to their herbivore-induced cotton host plants. Results also show that these responses are variable in time following herbivore damage to cotton plants, which further demonstrates how difficult it is to generalize about the functional significance of these interactions. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  8. Herbivore-Induced Changes in Cotton Modulates Reproductive Behavior in the Moth Spodoptera littoralis

    Directory of Open Access Journals (Sweden)

    Ali Zakir

    2017-05-01

    Full Text Available Plants produce chemical defense compounds to resist herbivore attack either by repelling the herbivores or attracting natural enemies of the herbivores. We have previously shown that volatile compounds from cotton released in response to herbivory by conspecifics reduce oviposition in cotton leafworm moth Spodoptera littoralis. It remained, however, unclear whether herbivore-induced changes also affect moth pre-mating and mating behaviors. In this study we examined the effect of herbivore-induced changes in cotton on reproductive behaviors i.e., female calling, male attraction and investment, and mating behavior in S. littoralis. We found a reduction in the number of females calling i.e., females releasing pheromone, in the presence of cotton plants damaged by larvae of S. littoralis compared to undamaged plants. Females also spent significantly less time calling and showed a delay in calling in the presence of damaged plants. Furthermore, males exhibited significantly delayed activation and reduced attraction toward female sex pheromone in the presence of damaged plants. We also found that mating success and the number of matings were significantly reduced in the presence of damaged plants whereas male investment i.e., spermatophore weight, was not affected. Thus, our study provides evidence that herbivory by conspecifics on host plants affect pre-mating and mating behaviors in an insect herbivore.

  9. Lima bean leaves exposed to herbivore-induced conspecific plant volatiles attract herbivores in addition to carnivores

    NARCIS (Netherlands)

    Horiuchi, J.I.; Arimura, G.I.; Ozawa, R.; Shimoda, T.; Dicke, M.; Takabayashi, J.; Nishioka, T.

    2003-01-01

    We tested the response of the herbivorous mite Tetranychus urticae to uninfested lima bean leaves exposed to herbivore-induced conspecific plant volatiles by using a Y-tube olfactometer. First, we confirmed that exposed uninfested leaves next to infested leaves were more attractive to carnivorous

  10. Herbivore-induced plant volatiles accurately predict history of coexistence, diet breadth, and feeding mode of herbivores.

    NARCIS (Netherlands)

    Danner, H.; Desurmont, G.A.; Cristescu, S.M.; Dam, N.M. van

    2017-01-01

    Herbivore-induced plant volatiles (HIPVs) serve as specific cues to higher trophic levels. Novel, exotic herbivores entering native foodwebs may disrupt the infochemical network as a result of changes in HIPV profiles. Here, we analysed HIPV blends of native Brassica rapa plants infested with one of

  11. Nocturnal herbivore-induced plant volatiles attract the generalist predatory earwig Doru luteipes Scudder

    Science.gov (United States)

    Naranjo-Guevara, Natalia; Peñaflor, Maria Fernanda G. V.; Cabezas-Guerrero, Milton F.; Bento, José Maurício S.

    2017-10-01

    Numerous studies have demonstrated that entomophagous arthropods use herbivore-induced plant volatile (HIPV) blends to search for their prey or host. However, no study has yet focused on the response of nocturnal predators to volatile blends emitted by prey damaged plants. We investigated the olfactory behavioral responses of the night-active generalist predatory earwig Doru luteipes Scudder (Dermaptera: Forficulidae) to diurnal and nocturnal volatile blends emitted by maize plants ( Zea mays) attacked by either a stem borer ( Diatraea saccharalis) or a leaf-chewing caterpillar ( Spodoptera frugiperda), both suitable lepidopteran prey. Additionally, we examined whether the earwig preferred odors emitted from short- or long-term damaged maize. We first determined the earwig diel foraging rhythm and confirmed that D. luteipes is a nocturnal predator. Olfactometer assays showed that during the day, although the earwigs were walking actively, they did not discriminate the volatiles of undamaged maize plants from those of herbivore damaged maize plants. In contrast, at night, earwigs preferred volatiles emitted by maize plants attacked by D. saccharalis or S. frugiperda over undamaged plants and short- over long-term damaged maize. Our GC-MS analysis revealed that short-term damaged nocturnal plant volatile blends were comprised mainly of fatty acid derivatives (i.e., green leaf volatiles), while the long-term damaged plant volatile blend contained mostly terpenoids. We also observed distinct volatile blend composition emitted by maize damaged by the different caterpillars. Our results showed that D. luteipes innately uses nocturnal herbivore-induced plant volatiles to search for prey. Moreover, the attraction of the earwig to short-term damaged plants is likely mediated by fatty acid derivatives.

  12. Green chemistry: highly selective biocatalytic hydrolysis of nitrile compounds

    CSIR Research Space (South Africa)

    Brady, D

    2006-02-28

    Full Text Available Nitrile substrate profiles were determined for a wide range of microorganisms. Isolated bacteria and yeast were enriched on nitriles as the sole nitrogen source. Aliphatic and aromatic nitriles were investigated, as well as structurally related...

  13. Herbivore-induced volatile emissions from cotton (Gossypium hirsutum L.) seedlings.

    Science.gov (United States)

    McCall, P J; Turlings, T C; Loughrin, J; Proveaux, A T; Tumlinson, J H

    1994-12-01

    The effect of herbivory on the composition of the volatile blends released by cotton seedlings was investigated by collecting volatiles from undamaged, freshly damaged (0-2 hr after initiation of feeding), and old damaged (16-19 hr after initiation of feeding) plants on which corn earworm caterpillars (Helicoverpa zea Boddie) were actively feeding. A blend of 22 compounds was consistently observed to be emitted by the old damaged plants with nine occurring either only in, or in significantly greater amounts in old damaged, as compared with freshly damaged plants. These were (Z)-3-hexenyl acetate, hexyl acetate, (E)-β-ocimene, (3E)-4,8-dimethyl-1,3,7-nonatriene, (Z)-3-hexenyl butyrate, (E)-2-hexenyl butyrate, (Z)-3-hexenyl 2-methylbutyrate, (E)-2-hexenyl 2-methylbutyrate, and indole. The nature of this response is compared with other studies where herbivore-induced volatile responses are also known. The presence of large amounts of terpenes and aldehydes seen at the onset of feeding and the appearance of other compounds hours later suggest that cotton defense mechanisms may consist of a constitutive repertoire that is augmented by an induced mechanism mobilized in response to attack. A number of the induced compounds are common to many plants where, in addition to an immediate defensive function, they are known to be involved in the attraction of natural enemies.

  14. Further field evaluation of synthetic herbivore-induced plant volatiles as attractants for beneficial insects.

    Science.gov (United States)

    James, David G

    2005-03-01

    Fifteen synthetic herbivore-induced plant volatiles (HIPVs) were field-tested for attractivity to beneficial insects in two experiments conducted in an open field and a hop yard in Washington State. Eleven insect species or families showed significant attraction to 13 HIPVs. The ladybeetle, Stethorus punctum picipes, was attracted to sticky traps baited with methyl salicylate (MeSA), cis-3-hexen-1-ol (He), and benzaldehyde (Be). The minute pirate bug, Orius tristicolor, was attracted to traps baited with MeSA, He, Be, and octyl aldehyde (Oa), and the bigeyed bug, Geocoris pallens, responded to MeSA, indole, and trans-2-hexen-1-al. The mymarid wasp, Anagrus daanei, was attracted to He, Oa, and farnesene. The chloropid fly, Thaumatomyia glabra, was highly attracted to methyl anthranilate. Insect families responding to HIPVs included Syrphidae (MeSA, He), Braconidae ((Z)-3-hexenyl acetate, He, cis-jasmone (J), methyl jasmonate (MeJA), methyl anthranilate (MeA)), Empididae (MeSA), Sarcophagidae (MeSA, Be, J, nonanal and geraniol), Tachinidae (Be), and Agromyzidae (MeSA). Micro-Hymenoptera (primarily parasitic wasp families) were attracted to MeSA, He, and indole. These results are discussed with respect to known properties and bioactivity of the tested HIPVs and to their potential as tools for recruiting natural enemies into agroecosystems.

  15. Elevated carbon dioxide reduces emission of herbivore-induced volatiles in Zea mays.

    Science.gov (United States)

    Block, Anna; Vaughan, Martha M; Christensen, Shawn A; Alborn, Hans T; Tumlinson, James H

    2017-09-01

    Terpene volatiles produced by sweet corn (Zea mays) upon infestation with pests such as beet armyworm (Spodoptera exigua) function as part of an indirect defence mechanism by attracting parasitoid wasps; yet little is known about the impact of climate change on this form of plant defence. To investigate how a central component of climate change affects indirect defence, we measured herbivore-induced volatile emissions in plants grown under elevated carbon dioxide (CO 2 ). We found that S. exigua infested or elicitor-treated Z. mays grown at elevated CO 2 had decreased emission of its major sesquiterpene, (E)-β-caryophyllene and two homoterpenes, (3E)-4,8-dimethyl-1,3,7-nonatriene and (3E,7E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene. In contrast, inside the leaves, elicitor-induced (E)-β-caryophyllene hyper-accumulated at elevated CO 2 , while levels of homoterpenes were unaffected. Furthermore, gene expression analysis revealed that the induction of terpene synthase genes following treatment was lower in plants grown at elevated CO 2 . Our data indicate that elevated CO 2 leads both to a repression of volatile synthesis at the transcriptional level and to limitation of volatile release through effects of CO 2 on stomatal conductance. These findings suggest that elevated CO 2 may alter the ability of Z. mays to utilize volatile terpenes to mediate indirect defenses. © 2017 John Wiley & Sons Ltd.

  16. Herbivore-Induced DNA Demethylation Changes Floral Signalling and Attractiveness to Pollinators in Brassica rapa.

    Science.gov (United States)

    Kellenberger, Roman T; Schlüter, Philipp M; Schiestl, Florian P

    2016-01-01

    Plants have to fine-tune their signals to optimise the trade-off between herbivore deterrence and pollinator attraction. An important mechanism in mediating plant-insect interactions is the regulation of gene expression via DNA methylation. However, the effect of herbivore-induced DNA methylation changes on pollinator-relevant plant signalling has not been systematically investigated. Here, we assessed the impact of foliar herbivory on DNA methylation and floral traits in the model crop plant Brassica rapa. Methylation-sensitive amplified fragment length polymorphism (MSAP) analysis showed that leaf damage by the caterpillar Pieris brassicae was associated with genome-wide methylation changes in both leaves and flowers of B. rapa as well as a downturn in flower number, morphology and scent. A comparison to plants with jasmonic acid-induced defence showed similar demethylation patterns in leaves, but both the floral methylome and phenotype differed significantly from P. brassicae infested plants. Standardised genome-wide demethylation with 5-azacytidine in five different B. rapa full-sib groups further resulted in a genotype-specific downturn of floral morphology and scent, which significantly reduced the attractiveness of the plants to the pollinator bee Bombus terrestris. These results suggest that DNA methylation plays an important role in adjusting plant signalling in response to changing insect communities.

  17. Subterranean, herbivore-induced plant volatile increases biological control activity of multiple beneficial nematode species in distinct habitats.

    Directory of Open Access Journals (Sweden)

    Jared G Ali

    Full Text Available While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs. However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene from citrus roots 9-12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests.

  18. Subterranean, Herbivore-Induced Plant Volatile Increases Biological Control Activity of Multiple Beneficial Nematode Species in Distinct Habitats

    Science.gov (United States)

    Ali, Jared G.; Alborn, Hans T.; Campos-Herrera, Raquel; Kaplan, Fatma; Duncan, Larry W.; Rodriguez-Saona, Cesar; Koppenhöfer, Albrecht M.; Stelinski, Lukasz L.

    2012-01-01

    While the role of herbivore-induced volatiles in plant-herbivore-natural enemy interactions is well documented aboveground, new evidence suggests that belowground volatile emissions can protect plants by attracting entomopathogenic nematodes (EPNs). However, due to methodological limitations, no study has previously detected belowground herbivore-induced volatiles in the field or quantified their impact on attraction of diverse EPN species. Here we show how a belowground herbivore-induced volatile can enhance mortality of agriculturally significant root pests. First, in real time, we identified pregeijerene (1,5-dimethylcyclodeca-1,5,7-triene) from citrus roots 9–12 hours after initiation of larval Diaprepes abbreviatus feeding. This compound was also detected in the root zone of mature citrus trees in the field. Application of collected volatiles from weevil-damaged citrus roots attracted native EPNs and increased mortality of beetle larvae (D. abbreviatus) compared to controls in a citrus orchard. In addition, field applications of isolated pregeijerene caused similar results. Quantitative real-time PCR revealed that pregeijerene increased pest mortality by attracting four species of naturally occurring EPNs in the field. Finally, we tested the generality of this root-zone signal by application of pregeijerene in blueberry fields; mortality of larvae (Galleria mellonella and Anomala orientalis) again increased by attracting naturally occurring populations of an EPN. Thus, this specific belowground signal attracts natural enemies of widespread root pests in distinct agricultural systems and may have broad potential in biological control of root pests. PMID:22761668

  19. Nitrile Metabolizing Enzymes in Biocatalysis and Biotransformation.

    Science.gov (United States)

    Bhalla, Tek Chand; Kumar, Vijay; Kumar, Virender; Thakur, Neerja; Savitri

    2018-01-30

    Nitrile metabolizing enzymes, i.e., aldoxime dehydratase, hydroxynitrile lyase, nitrilase, nitrile hydratase, and amidase, are the key catalysts in carbon nitrogen triple bond anabolism and catabolism. Over the past several years, these enzymes have drawn considerable attention as prominent biocatalysts in academia and industries because of their wide applications. Research on various aspects of these biocatalysts, i.e., sources, screening, function, purification, molecular cloning, structure, and mechanisms, has been conducted, and bioprocesses at various scales have been designed for the synthesis of myriads of useful compounds. This review is focused on the potential of nitrile metabolizing enzymes in the production of commercially important fine chemicals such as nitriles, carboxylic acids, and amides. A number of opportunities and challenges of nitrile metabolizing enzymes in bioprocess development for the production of bulk and fine chemicals are discussed.

  20. Herbivore-induced chemical and molecular responses of the kelps Laminaria digitata and Lessonia spicata.

    Directory of Open Access Journals (Sweden)

    Andrés Ritter

    herbivore-induced chemical and molecular responses in kelp species, showing similar inducible responses upon specialist herbivores in their respective ecosystems.

  1. Ozone exposure triggers the emission of herbivore-induced plant volatiles, but does not disturb tritrophic signalling

    Energy Technology Data Exchange (ETDEWEB)

    Vuorinen, Terhi; Nerg, Anne-Marja; Holopainen, Jarmo K

    2004-09-01

    We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-{beta}-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs for attraction of the natural enemies of herbivores may have adaptive coevolution. However, the expected elevated ozone concentrations in future may not disturb tritrophic signalling, unless herbivore-induced VOCs are lost in the process of aerosol formation.

  2. Nitrile Polymerisation and Heterocyclic Synthesis Using Iminyls.

    Science.gov (United States)

    1977-03-31

    methoxyamine in acidic ethanol solution the corresponding ethyl acecal was formed. In an alternative approach to the keto—nitrile (7; X—CN) the lactone (9) was... unsaturated nitrile. In this way the keto—nitrile (15) was ~~~ (i5~) (“) (1 7) LI produced but only in Low yield .7 The main products, the 2:1 adduc ts...2H , s , Cl!2), 7.23—7.68 (50, is , ArH); (b) the lactone of ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ --- —— - .5---- -- . . 5 - — - - . -~~~~ -- --.5

  3. A genetically-based latitudinal cline in the emission of herbivore-induced plant volatile organic compounds.

    Science.gov (United States)

    Wason, Elizabeth L; Agrawal, Anurag A; Hunter, Mark D

    2013-08-01

    The existence of predictable latitudinal variation in plant defense against herbivores remains controversial. A prevailing view holds that higher levels of plant defense evolve at low latitudes compared to high latitudes as an adaptive plant response to higher herbivore pressure on low-latitude plants. To date, this prediction has not been examined with respect to volatile organic compounds (VOCs) that many plants emit, often thus attracting the natural enemies of herbivores. Here, we compared genetically-based constitutive and herbivore-induced aboveground vegetative VOC emissions from plants originating across a gradient of more than 10° of latitude (>1,500 km). We collected headspace VOCs from Asclepias syriaca (common milkweed) originating from 20 populations across its natural range and grown in a common garden near the range center. Feeding by specialist Danaus plexippus (monarch) larvae induced VOCs, and field environmental conditions (temperature, light, and humidity) also influenced emissions. Monarch damage increased plant VOC concentrations and altered VOC blends. We found that genetically-based induced VOC emissions varied with the latitude of plant population origin, although the pattern followed the reverse of that predicted-induced VOC concentration increased with increasing latitude. This pattern appeared to be driven by a greater induction of sesquiterpenoids at higher latitudes. In contrast, constitutive VOC emission did not vary systematically with latitude, and the induction of green leafy volatiles declined with latitude. Our results do not support the prevailing view that plant defense is greater at lower than at higher latitudes. That the pattern holds only for herbivore-induced VOC emission, and not constitutive emission, suggests that latitudinal variation in VOCs is not a simple adaptive response to climatic factors.

  4. The effects of herbivore-induced plant volatiles on interactions between plants and flower-visiting insects.

    Science.gov (United States)

    Lucas-Barbosa, Dani; van Loon, Joop J A; Dicke, Marcel

    2011-09-01

    Plants are faced with a trade-off between on the one hand growth, development and reproduction and on the other hand defence against environmental stresses. Yet, research on insect-plant interactions has addressed plant-pollinator interactions and plant-attacker interactions separately. Plants have evolved a high diversity of constitutive and induced responses to attack, including the systemic emission of herbivore-induced plant volatiles (HIPVs). The effect of HIPVs on the behaviour of carnivorous insects has received ample attention for leaf-feeding (folivorous) species and their parasitoids and predators. Here, we review whether and to what extent HIPVs affect the interaction of plants in the flowering stage with mutualistic and antagonistic insects. Whereas the role of flower volatiles in the interactions between plants and insect pollinators has received increased attention over the last decade, studies addressing both HIPVs and pollinator behaviour are rare, despite the fact that in a number of plant species herbivory is known to affect flower traits, including size, nectar secretion and composition. In addition, folivory and florivory can also result in significant changes in flower volatile emission and in most systems investigated, pollinator visitation decreased, although exceptions have been found. Negative effects of HIPVs on pollinator visitation rates likely exert negative selection pressure on HIPV emission. The systemic nature of herbivore-induced plant responses and the behavioural responses of antagonistic and mutualistic insects, requires the study of volatile emission of entire plants in the flowering stage. We conclude that approaches to integrate the study of plant defences and pollination are essential to advance plant biology, in particular in the context of the trade-off between defence and growth/reproduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Combined use of herbivore-induced plant volatiles and sex pheromones for mate location in braconid parasitoids.

    Science.gov (United States)

    Xu, Hao; Desurmont, Gaylord; Degen, Thomas; Zhou, Guoxin; Laplanche, Diane; Henryk, Luka; Turlings, Ted C J

    2017-03-01

    Herbivore-induced plant volatiles (HIPVs) are important cues for female parasitic wasps to find hosts. Here, we investigated the possibility that HIPVs may also serve parasitoids as cues to locate mates. To test this, the odour preferences of four braconid wasps - the gregarious parasitoid Cotesia glomerata (L.) and the solitary parasitoids Cotesia marginiventris (Cresson), Microplitis rufiventris Kokujev and Microplitis mediator (Haliday) - were studied in olfactometers. Each species showed attraction to pheromones but in somewhat different ways. Males of the two Cotesia species were attracted to virgin females, whereas females of M. rufiventris were attracted to virgin males. Male and female M. mediator exhibited attraction to both sexes. Importantly, female and male wasps of all four species were strongly attracted by HIPVs, independent of mating status. In most cases, male wasps were also attracted to intact plants. The wasps preferred the combination of HIPVs and pheromones over plant odours alone, except M. mediator, which appears to mainly use HIPVs for mate location. We discuss the ecological contexts in which the combined use of pheromones and HIPVs by parasitoids can be expected. To our knowledge, this is the first study to show that braconid parasitoids use HIPVs and pheromones in combination to locate mates. © 2016 John Wiley & Sons Ltd.

  6. Foraging leaf-cutting ants learn to reject Vitis vinifera ssp. vinifera plants that emit herbivore-induced volatiles.

    Science.gov (United States)

    Thiele, Theresa; Kost, Christian; Roces, Flavio; Wirth, Rainer

    2014-06-01

    Leaf-cutting ants (LCAs) are dominant herbivores of the Neotropics, as well as economically important pests. Their foraging ecology and patterns/mechanisms of food selection have received considerable attention. Recently, it has been documented that LCAs exhibit a delayed rejection of previously accepted food plants following treatment with a fungicide that makes the plants unsuitable as substrate for their symbiotic fungus. Here, we investigated whether LCAs similarly reject plants with induced chemical defenses, by combining analysis of volatile emissions with dual-choice bioassays that used LCA subcolonies (Atta sexdens L.). On seven consecutive days, foraging ants were given the choice between leaf disks from untreated control plants and test plants of Vitis vinifera ssp. vinifera L. treated with the phytohormone jasmonic acid (JA) to mimic herbivore attack. Chemical analysis revealed the emission of a characteristic set of herbivore-induced volatile organic compounds (VOC) from JA-induced plants. Dual-choice experiments indicated that workers did not show any preference initially, but that they avoided JA-treated plants from day five onwards. Our finding that A. sexdens foragers learn to avoid VOC-emitting plants, which are likely detrimental to their symbiotic fungus, represents the first evidence for avoidance learning in attine ants toward plants with induced defenses.

  7. The Herbivore-Induced Plant Volatiles Methyl Salicylate and Menthol Positively affect Growth and Pathogenicity of Entomopathogenic Fungi

    Science.gov (United States)

    Lin, Yongwen; Qasim, Muhammad; Hussain, Mubasher; Akutse, Komivi Senyo; Avery, Pasco Bruce; Dash, Chandra Kanta; Wang, Liande

    2017-01-01

    Some herbivore-induced-plant volatiles (HIPVs) compounds are vital for the functioning of an ecosystem, by triggering multi-trophic interactions for natural enemies, plants and herbivores. However, the effect of these chemicals, which play a crucial role in regulating the multi-trophic interactions between plant-herbivore-entomopathogenic fungi, is still unknown. To fill this scientific gap, we therefore investigated how these chemicals influence the entomopathogenic fungi growth and efficacy. In this study, Lipaphis erysimi induced Arabidopsis thaliana HIPVs were collected using headspace system and detected with GC-MS, and then analyzed the effects of these HIPVs chemicals on Lecanicillium lecanii strain V3450. We found that the HIPVs menthol and methyl salicylate at 1 and 10 nmol·ml-1 improved many performance aspects of the fungus, such as germination, sporulation, appressorial formation as well as its pathogenicity and virulence. These findings are not only important for understanding the multi-trophic interactions in an ecosystem, but also would contribute for developing new and easier procedures for conidial mass production as well as improve the pathogenicity and virulence of entomopathogenic fungi in biological pest management strategies.

  8. Constitutive and herbivore-induced systemic volatiles differentially attract an omnivorous biocontrol agent to contrasting Salix clones.

    Science.gov (United States)

    Lehrman, Anna; Boddum, Tina; Stenberg, Johan A; Orians, Colin M; Björkman, Christer

    2013-01-01

    While carnivores are known to be attracted to herbivore-induced plant volatiles, little is known about how such volatiles may affect the behaviour of omnivorous predators that may use both plants and herbivores as food. Here, we examine how systemically produced plant volatiles, in response to local herbivore damage, differentially attract a key omnivorous predator, Anthocoris nemorum (Heteroptera: Anthocoridae), to single clones of three species of Salix: S. viminalis, S. dasyclados and S. cinerea. The profiles of the plant volatiles produced were found to vary among Salix clones and between herbivore-damaged and intact plants. Anthocoris nemorum was attracted to the volatiles released from undamaged plants of all three species, but most strongly to a native S. cinerea clone. Plants damaged by the herbivorous leaf beetle Phratora vulgatissima (Coleoptera: Chrysomelidae) were generally more attractive than undamaged plants, with A. nemorum responding to systemic changes in the damaged plants where the experimental design specifically excluded volatiles released from the actual site of damage. When comparing damaged plants, the S. dasyclados clone was more attractive to A. nemorum than the S. viminalis clone-a somewhat surprising result since this Salix clone is considered relatively resistant to P. vulgatissima, and hence offers a limited amount of prey. Our experiments highlight that both constitutive and induced plant volatiles play a role in omnivore attraction, and this emphasizes the importance of considering odours of released volatiles when cropping and breeding Salix for increased resistance to herbivores.

  9. OsNPR1 negatively regulates herbivore-induced JA and ethylene signaling and plant resistance to a chewing herbivore in rice.

    Science.gov (United States)

    Li, Ran; Afsheen, Sumera; Xin, Zhaojun; Han, Xiu; Lou, Yonggen

    2013-03-01

    NPR1 (a non-expressor of pathogenesis-related genes1) has been reported to play an important role in plant defense by regulating signaling pathways. However, little to nothing is known about its function in herbivore-induced defense in monocot plants. Here, using suppressive substrate hybridization, we identified a NPR1 gene from rice, OsNPR1, and found that its expression levels were upregulated in response to infestation by the rice striped stem borer (SSB) Chilo suppressalis and rice leaf folder (LF) Cnaphalocrocis medinalis, and to mechanical wounding and treatment with jasmonic acid (JA) and salicylic acid (SA). Moreover, mechanical wounding induced the expression of OsNPR1 quickly, whereas herbivore infestation induced the gene more slowly. The antisense expression of OsNPR1 (as-npr1), which reduced the expression of the gene by 50%, increased elicited levels of JA and ethylene (ET) as well as of expression of a lipoxygenase gene OsHI-LOX and an ACC synthase gene OsACS2. The enhanced JA and ET signaling in as-npr1 plants increased the levels of herbivore-induced trypsin proteinase inhibitors (TrypPIs) and volatiles, and reduced the performance of SSB. Our results suggest that OsNPR1 is an early responding gene in herbivore-induced defense and that plants can use it to activate a specific and appropriate defense response against invaders by modulating signaling pathways. Copyright © Physiologia Plantarum 2012.

  10. Biotransformation of nitriles to hydroxamic acids via a nitrile hydratase–amidase cascade reaction

    Czech Academy of Sciences Publication Activity Database

    Vejvoda, Vojtěch; Martínková, Ludmila; Veselá, Alicja Barbara; Kaplan, Ondřej; Lutz-Wahl, S.; Fischer, L.; Uhnáková, Bronislava

    2011-01-01

    Roč. 71, 1-2 (2011), s. 51-55 ISSN 1381-1177 R&D Projects: GA MŠk(CZ) LC06010; GA MŠk OC09046 Institutional research plan: CEZ:AV0Z50200510 Keywords : Nitrile hydratase * Rhodococcus erythropolis * Amidase Subject RIV: EE - Microbiology, Virology Impact factor: 2.735, year: 2011

  11. Silicon Supplementation Alters the Composition of Herbivore Induced Plant Volatiles and Enhances Attraction of Parasitoids to Infested Rice Plants

    Directory of Open Access Journals (Sweden)

    Jian Liu

    2017-07-01

    Full Text Available Silicon (Si is important in plant defenses that operate in a direct manner against herbivores, and work in rice (Oryza sativa has established that this is mediated by the jasmonate signaling pathway. Plant defenses also operate indirectly, by the production of herbivore induced plant volatiles (HIPVs that attract predators and parasitoids of herbivores. These indirect defenses too are mediated by the jasmonate pathway but no earlier work has demonstrated an effect of Si on HIPVs. In this study, we tested the effect of Si supplementation versus Si deprivation to rice plants on subsequent HIPV production following feeding by the important pest, rice leaffolder (Cnaphalocrocis medinalis. Gas chromatography–mass spectrometry analyses showed lower production of α-bergamotene, β-sesquiohellandrene, hexanal 2-ethyl, and cedrol from +Si herbivore-infested plants compared with -Si infested plants. These changes in plant chemistry were ecologically significant in altering the extent to which parasitoids were attracted to infested plants. Adult females of Trathala flavo-orbitalis and Microplitis mediator both exhibited greater attraction to the HIPV blend of +Si plants infested with their respective insect hosts compared to -Si infested plants. In equivalent studies using RNAi rice plants in which jasmonate perception was silenced there was no equivalent change to the HIPV blend associated with Si treatment; indicating that the effects of Si on HIPVs are modulated by the jasmonate pathway. Further, this work demonstrates that silicon alters the HIPV blend of herbivore-infested rice plants. The significance of this finding is that there are no earlier-published studies of this phenomenon in rice or any other plant species. Si treatment to crops offers scope for enhancing induced, indirect defenses and associated biological control of pests because parasitoids are more strongly attracted by the HIPVs produced by +Si plants.

  12. Silicon Supplementation Alters the Composition of Herbivore Induced Plant Volatiles and Enhances Attraction of Parasitoids to Infested Rice Plants.

    Science.gov (United States)

    Liu, Jian; Zhu, Jiwei; Zhang, Pengjun; Han, Liwei; Reynolds, Olivia L; Zeng, Rensen; Wu, Jinhong; Shao, Yue; You, Minsheng; Gurr, Geoff M

    2017-01-01

    Silicon (Si) is important in plant defenses that operate in a direct manner against herbivores, and work in rice (Oryza sativa) has established that this is mediated by the jasmonate signaling pathway. Plant defenses also operate indirectly, by the production of herbivore induced plant volatiles (HIPVs) that attract predators and parasitoids of herbivores. These indirect defenses too are mediated by the jasmonate pathway but no earlier work has demonstrated an effect of Si on HIPVs. In this study, we tested the effect of Si supplementation versus Si deprivation to rice plants on subsequent HIPV production following feeding by the important pest, rice leaffolder (Cnaphalocrocis medinalis). Gas chromatography-mass spectrometry analyses showed lower production of α-bergamotene, β-sesquiohellandrene, hexanal 2-ethyl, and cedrol from +Si herbivore-infested plants compared with -Si infested plants. These changes in plant chemistry were ecologically significant in altering the extent to which parasitoids were attracted to infested plants. Adult females of Trathala flavo-orbitalis and Microplitis mediator both exhibited greater attraction to the HIPV blend of +Si plants infested with their respective insect hosts compared to -Si infested plants. In equivalent studies using RNAi rice plants in which jasmonate perception was silenced there was no equivalent change to the HIPV blend associated with Si treatment; indicating that the effects of Si on HIPVs are modulated by the jasmonate pathway. Further, this work demonstrates that silicon alters the HIPV blend of herbivore-infested rice plants. The significance of this finding is that there are no earlier-published studies of this phenomenon in rice or any other plant species. Si treatment to crops offers scope for enhancing induced, indirect defenses and associated biological control of pests because parasitoids are more strongly attracted by the HIPVs produced by +Si plants.

  13. Differential Performance and Parasitism of Caterpillars on Maize Inbred Lines with Distinctly Different Herbivore-Induced Volatile Emissions

    Science.gov (United States)

    Degen, Thomas; Bakalovic, Nenad; Bergvinson, David; Turlings, Ted C. J.

    2012-01-01

    Plant volatiles induced by insect feeding are known to attract natural enemies of the herbivores. Six maize inbred lines that showed distinctly different patterns of volatile emission in laboratory assays were planted in randomized plots in the Central Mexican Highlands to test their ability to recruit parasitic wasps under field conditions. The plants were artificially infested with neonate larvae of the fall armyworm Spodoptera frugiperda, and two of its main endoparasitoids, Campoletis sonorensis and Cotesia marginiventris, were released in the plots. Volatiles were collected from equally treated reference plants in the neighbourhood of the experimental field. The cumulative amount of 36 quantified volatile compounds determined for each line was in good accordance with findings from the laboratory; there was an almost 15-fold difference in total emission between the two extreme lines. We found significant differences among the lines with respect to the numbers of armyworms recovered from the plants, their average weight gain and parasitism rates. Average weight of the caterpillars was negatively correlated with the average total amount of volatiles released by the six inbred lines. However, neither total volatile emission nor any specific single compound within the blend could explain the differential parasitism rates among the lines, with the possible exception of (E)-2-hexenal for Campoletis sonorensis and methyl salicylate for Cotesia marginiventris. Herbivore-induced plant volatiles and/or correlates thereof contribute to reducing insect damage of maize plants through direct plant defence and enhanced attraction of parasitoids, alleged indirect defence. The potential to exploit these volatiles for pest control deserves to be further evaluated. PMID:23112820

  14. Herbivore-induced volatiles in the perennial shrub, Vaccinium corymbosum, and their role in inter-branch signaling.

    Science.gov (United States)

    Rodriguez-Saona, Cesar R; Rodriguez-Saona, Luis E; Frost, Christopher J

    2009-02-01

    Herbivore feeding activates plant defenses at the site of damage as well as systemically. Systemic defenses can be induced internally by signals transported via phloem or xylem, or externally transmitted by volatiles emitted from the damaged tissues. We investigated the role of herbivore-induced plant volatiles (HIPVs) in activating a defense response between branches in blueberry plants. Blueberries are perennial shrubs that grow by initiating adventitious shoots from a basal crown, which produce new lateral branches. This type of growth constrains vascular connections between shoots and branches within plants. While we found that leaves within a branch were highly connected, vascular connectivity was limited between branches within shoots and absent between branches from different shoots. Larval feeding by gypsy moth, exogenous methyl jasmonate, and mechanical damage differentially induced volatile emissions in blueberry plants, and there was a positive correlation between amount of insect damage and volatile emission rates. Herbivore damage did not affect systemic defense induction when we isolated systemic branches from external exposure to HIPVs. Thus, internal signals were not capable of triggering systemic defenses among branches. However, exposure of branches to HIPVs from an adjacent branch decreased larval consumption by 70% compared to those exposed to volatiles from undamaged branches. This reduction in leaf consumption did not result in decreased volatile emissions, indicating that leaves became more responsive to herbivory (or "primed") after being exposed to HIPVs. Chemical profiles of leaves damaged by gypsy moth caterpillars, exposed to HIPVs, or non-damaged controls revealed that HIPV-exposed leaves had greater chemical similarities to damaged leaves than to control leaves. Insect-damaged leaves and young HIPV-exposed leaves had higher amounts of endogenous cis-jasmonic acid compared to undamaged and non-exposed leaves, respectively. Our results

  15. Differential performance and parasitism of caterpillars on maize inbred lines with distinctly different herbivore-induced volatile emissions.

    Directory of Open Access Journals (Sweden)

    Thomas Degen

    Full Text Available Plant volatiles induced by insect feeding are known to attract natural enemies of the herbivores. Six maize inbred lines that showed distinctly different patterns of volatile emission in laboratory assays were planted in randomized plots in the Central Mexican Highlands to test their ability to recruit parasitic wasps under field conditions. The plants were artificially infested with neonate larvae of the fall armyworm Spodoptera frugiperda, and two of its main endoparasitoids, Campoletis sonorensis and Cotesia marginiventris, were released in the plots. Volatiles were collected from equally treated reference plants in the neighbourhood of the experimental field. The cumulative amount of 36 quantified volatile compounds determined for each line was in good accordance with findings from the laboratory; there was an almost 15-fold difference in total emission between the two extreme lines. We found significant differences among the lines with respect to the numbers of armyworms recovered from the plants, their average weight gain and parasitism rates. Average weight of the caterpillars was negatively correlated with the average total amount of volatiles released by the six inbred lines. However, neither total volatile emission nor any specific single compound within the blend could explain the differential parasitism rates among the lines, with the possible exception of (E-2-hexenal for Campoletis sonorensis and methyl salicylate for Cotesia marginiventris. Herbivore-induced plant volatiles and/or correlates thereof contribute to reducing insect damage of maize plants through direct plant defence and enhanced attraction of parasitoids, alleged indirect defence. The potential to exploit these volatiles for pest control deserves to be further evaluated.

  16. A cobalt-containing eukaryotic nitrile hydratase.

    Science.gov (United States)

    Martinez, Salette; Yang, Xinhang; Bennett, Brian; Holz, Richard C

    2017-01-01

    Nitrile hydratase (NHase), an industrially important enzyme that catalyzes the hydration of nitriles to their corresponding amides, has only been characterized from prokaryotic microbes. The putative NHase from the eukaryotic unicellular choanoflagellate organism Monosiga brevicollis (MbNHase) was heterologously expressed in Escherichia coli. The resulting enzyme expressed as a single polypeptide with fused α- and β-subunits linked by a seventeen-histidine region. Size-exclusion chromatography indicated that MbNHase exists primarily as an (αβ)2 homodimer in solution, analogous to the α2β2 homotetramer architecture observed for prokaryotic NHases. The NHase enzyme contained its full complement of Co(III) and was fully functional without the co-expression of an activator protein or E. coli GroES/EL molecular chaperones. The homology model of MbNHase was developed identifying Cys400, Cys403, and Cys405 as active site ligands. The results presented here provide the first experimental data for a mature and active eukaryotic NHase with fused subunits. Since this new member of the NHase family is expressed from a single gene without the requirement of an activator protein, it represents an alternative biocatalyst for industrial syntheses of important amide compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Onset of herbivore-induced resistance in systemic tissue primed for jasmonate-dependent defenses is activated by abscisic acid

    Directory of Open Access Journals (Sweden)

    Irene A. Vos

    2013-12-01

    Full Text Available In Arabidopsis, the MYC2 transcription factor on the one hand and the AP2/ERF transcription factors ORA59 and ERF1 on the other hand regulate distinct branches of the jasmonic acid (JA signaling pathway in an antagonistic fashion, co-regulated by abscisic acid (ABA and ethylene, respectively. Feeding by larvae of the specialist herbivorous insect Pieris rapae (small cabbage white butterfly results in activation of the MYC-branch and concomitant suppression of the ERF-branch in insect-damaged leaves. Here we investigated differential JA signaling activation in undamaged systemic leaves of P. rapae-infested plants. We found that the MYC2 transcription factor gene was induced both in the local insect-damaged leaves and the systemic undamaged leaves of P. rapae-infested Arabidopsis plants. However, in contrast to the insect-damaged leaves, the undamaged tissue did not show activation of the MYC-branch marker gene VSP1. Comparison of the hormone signal signature revealed that the levels of JA and (+-7-iso-jasmonoyl-L-isoleucine (JA-Ile raised to similar extents in locally damaged and systemically undamaged leaves, but the production of ABA and the JA precursor 12-oxo-phytodienoic acid (OPDA was enhanced only in the local herbivore-damaged leaves, and not in the distal undamaged leaves. Challenge of undamaged leaves of pre-infested plants with either P. rapae larvae or exogenously applied ABA led to potentiated expression levels of MYC2 and VSP1, with the latter reaching extremely high expression levels. Moreover, P. rapae-induced resistance, as measured by reduction of caterpillar growth on pre-infested plants, was blocked in the ABA biosynthesis mutant aba2-1, that was also impaired in P. rapae-induced expression of VSP1. Together, these results suggest that ABA is a crucial regulator of herbivore-induced resistance by activating primed JA-regulated defense responses upon secondary herbivore attack in Arabidopsis.

  18. Polybenzoxazole-filled nitrile butadiene rubber compositions

    Science.gov (United States)

    Gajiwala, Himansu M. (Inventor); Guillot, David G. (Inventor)

    2008-01-01

    An insulation composition that comprises at least one nitrile butadiene rubber (NBR) having an acrylonitrile content that ranges from approximately 26% by weight to approximately 35% by weight and polybenzoxazole (PBO) fibers. The NBR may be a copolymer of acrylonitrile and butadiene and may be present in the insulation composition in a range of from approximately 45% by weight to approximately 56% by weight of a total weight of the insulation composition. The PBO fibers may be present in a range of from approximately 3% by weight to approximately 10% by weight of a total weight of the insulation composition. A rocket motor including the insulation composition and a method of insulating a rocket motor are also disclosed.

  19. Characterisation of nitrilase and nitrile hydratase biocatalytic systems

    CSIR Research Space (South Africa)

    Brady, D

    2004-03-01

    Full Text Available range of alpha-hydroxy carboxylic acids or amides from aldehydes in the presence of cyanide. The use of an amidase inhibitor permits halting the nitrile hydratase/amidase reaction at the amide intermediate....

  20. Hydrolysis of nitriles by soil bacteria: variation with soil origin.

    Science.gov (United States)

    Rapheeha, O K L; Roux-van der Merwe, M P; Badenhorst, J; Chhiba, V; Bode, M L; Mathiba, K; Brady, D

    2017-03-01

    The aim of this study was to explore bacterial soil diversity for nitrile biocatalysts, in particular, those for hydrolysis of β-substituted nitriles, to the corresponding carboxamides and acids that may be incorporated into peptidomimetics. To achieve this, we needed to compare the efficiency of isolation methods and determine the influence of land use and geographical origin of the soil sample. Nitrile-utilizing bacteria were isolated from various soil environments across a 1000 km long transect of South Africa, including agricultural soil, a gold mine tailing dam and uncultivated soil. The substrate profile of these isolates was determined through element-limited growth studies on seven different aliphatic or aromatic nitriles. A subset of these organisms expressing broad substrate ranges was evaluated for their ability to hydrolyse β-substituted nitriles (3-amino-3-phenylpropionitrile and 3-hydroxy-4-phenoxybutyronitrile) and the active organisms were found to be Rhodococcus erythropolis from uncultivated soil and Rhodococcus rhodochrous from agricultural soils. The capacity for hydrolysis of β-substituted nitriles appears to reside almost exclusively in Rhodococci. Land use has a much greater effect on the biocatalysis substrate profile than geographical location. Enzymes are typically substrate specific in their catalytic reactions, and this means that a wide diversity of enzymes is required to provide a comprehensive biocatalysis toolbox. This paper shows that the microbial diversity of nitrile hydrolysis activity can be targeted according to land utilization. Nitrile biocatalysis is a green chemical method for the enzymatic production of amides and carboxylic acids that has industrial applications, such as in the synthesis of acrylamide and nicotinamide. The biocatalysts discovered in this study may be applied to the synthesis of peptidomimetics which are an important class of therapeutic compounds. © 2016 The Society for Applied Microbiology.

  1. Nitrile functionalized halloysite nanotubes/poly(arylene ether nitrile) nanocomposites: Interface control, characterization, and improved properties

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Xinyi [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); Zhan, Yingqing, E-mail: 201599010032@swpu.edu.cn [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, Sichuan, China, 610500 (China); Zeng, Guangyong [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); He, Yi, E-mail: heyi007@163.com [School of Chemistry and Chemical Engineering, Southwest Petroleum University, 8 Xindu Avenue, Chengdu, Sichuan, 610500 (China); Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, Sichuan, China, 610500 (China); State Key Lab of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, 8Xindu Avenue, Chengdu, Sichuan, 610500 (China)

    2017-01-30

    Highlights: • Novel nitrile functionalized HNTs were realized through the covalent bonding. • Then modified HNTs showed good dispersion and interfacial adhesion with PEN. • The modified HNTs exhibited excellent reinforcement effect on PEN. • The chemical crosslinking between HNTs and PEN further enhanced the performance of nanocomposites. - Abstract: To develop high-performance halloysite nanotube (HNT)-based nanocomposites, the two key issues need to be considered: precise interface control and the dispersal of HNTs. This study presents an efficient way to functionalize halloysite nanotubes with 3-aminophenoxy-phthalonitrile, followed by compounding with poly(arylene ether nitrile) (PEN), to prepare functional nanocomposite films. The surface functionalization of HNTs was characterized and confirmed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Compared with neat PEN, the tensile strength and modulus of the resulting PEN nanocomposites with 3 wt% functionalized HNTs were found to increase by 25.7% and 20.7%, respectively. The good dispersion and high capacitance of the dielectric layer resulted in PEN/HNTs nancomposites with enhanced dielectric permittivity and relatively low dielectric loss. Moreover, the addition of functional HNTs greatly improved the thermal stability of PEN, which could be further enhanced through the chemical cross-linking reaction between the functional HNTs and the PEN matrix. This work provides a new path toward obtaining advanced polymer-based nanocomposites with functional properties.

  2. Characterisation of the nitrile biocatalytic activity of rhodococcus rhodochrous ATCC BAA-870

    CSIR Research Space (South Africa)

    Frederick, J

    2006-10-01

    Full Text Available A versatile nitrile-degrading bacterium, Rhodococcus rhodochrous ATCC BAA-870, was isolated through enrichment culturing of soil samples from Johannesburg, South Africa. Useful nitrile-metabolising activity of a potential biocatalyst, Rhodococcus...

  3. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by the...

  4. Hydrogenated nitrile rubber for improved durability of automotive rubber parts

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, J.; Leibbrandt, F.; Thoermer, J.

    1987-01-01

    Rubber articles with improved heat resistance and better performance characteristics are becoming of increasing importance for the automotive industry. A new type of elastomer has therefore been developed based on saturated hydrocarbon backbone - for improved heat resistance - with nitrile side groups providing good resistance to swelling. Some of the typical characteristics of hydrogenated nitrile rubber (HNBR) vulcanizates such as good physical properties pattern at elevated low temperatures dynamic properties, ozone resistance and swelling in automotive fluids are discussed. Potential applications are suggested to improve the performance of various rubber parts used in automotive applications such as high performance seals.

  5. Investigation of surface halide modification of nitrile butadiene rubber

    Science.gov (United States)

    Sukhareva, K. V.; Mikhailov, I. A.; Andriasyan, Yu O.; Mastalygina, E. E.; Popov, A. A.

    2017-12-01

    The investigation is devoted to the novel technology of surface halide modification of rubber samples based on nitrile butadiene rubber (NBR). 1,1,2-trifluoro-1,2,2-trichlorethane was used as halide modifier. The developed technology is characterized by production stages reduction to one by means of treating the rubber compound with a halide modifier. The surface halide modification of compounds based on nitrile butadiene rubber (NBR) was determined to result in increase of resistance to thermal oxidation and aggressive media. The conducted research revealed the influence of modification time on chemical resistance and physical-mechanical properties of rubbers under investigation.

  6. Spectrometric Study of the Nitrile-Ketenimine Tautomerism

    Directory of Open Access Journals (Sweden)

    Hebe Saraví Cisneros

    2009-01-01

    Full Text Available Mass spectrometry is used to evaluate the occurrence of the nitrile-ketenimine tautomerism. Mass spectra of two differently substituted nitriles, ethyl-4,4-dicyano-3-methyl-3-butenoate and diethyl-2-cyano-3-methyl-2-pentenodiate are examined looking for common mass spectral behaviors. Ion fragmentation assignments for specific tautomers allow to predict the presence of the corresponding structures. Additionally, the mass spectrum and nuclear magnetic resonance spectra of ethyl-4,4-dicyano-2,2-diethyl-3-methyl-3-butenoate and that of the corresponding amination product support the occurrence of the ketenimine tautomer in the equilibrium.

  7. The Reduction of Nitriles to Aldehydes: Applications of Raney Nickel ...

    African Journals Online (AJOL)

    NJD

    sive in contact with oxidizers; it is not considered a fire hazard but forms spontaneously flammable phosphine gas when heated. In the absence of a metal catalyst, it has been used under microwave irradiation selectively to reduce the nitro group into an amino group; certain common functional groups including nitrile are ...

  8. Hydrolysis of nitriles by soil bacteria: variation with soil origin

    CSIR Research Space (South Africa)

    Rapheeha, OKL

    2017-03-01

    Full Text Available . To achieve this, we needed to compare the efficiency of isolation methods and determine the influence of land use and geographical origin of the soil sample. Nitrile-utilizing bacteria were isolated from various soil environments across a 1000 km long...

  9. 40 CFR 721.555 - Alkyl amino nitriles (generic).

    Science.gov (United States)

    2010-07-01

    ....555 Section 721.555 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC... to reporting. (1) The chemical substances identified generically as alkyl amino nitriles (PMNs P-96.... The provisions of subpart A of this part apply to this section except as modified by this paragraph...

  10. Green chemistry: highly selective biocatalytic hydrolysis of nitrile compounds

    CSIR Research Space (South Africa)

    Brady, D

    2006-09-01

    Full Text Available The application of highly substrate-specific catalysts, such as biocatalysts, can reduce the number of synthetic steps required to generate organic compounds. A wide range of bacteria and yeast cultures were enriched on nitriles as the sole source...

  11. Platinum-Catalyzed Selective Hydration of Hindered Nitriles and Nitriles with Acid- or Base-Sensitive Groups

    NARCIS (Netherlands)

    Jiang, Xiao-bin; Minnaard, Adriaan J.; Vries, Johannes G. de; Feringa, Bernard

    2004-01-01

    Hindered tertiary nitriles can be hydrolyzed under neutral and mild conditions to the corresponding amides using platinum(II) catalysts with dimethylphosphine oxide or other secondary phosphine oxides (SPOs, phosphinous acids) as ligands. We have found that this procedure also works well for

  12. Field evaluation of herbivore-induced plant volatiles as attractants for beneficial insects: methyl salicylate and the green lacewing, Chrysopa nigricornis.

    Science.gov (United States)

    James, David G

    2003-07-01

    Synthetic methyl salicylate (MeSA), a herbivore-induced plant volatile (HIPV), was demonstrated to be an attractant for the green lacewing, Chrysopa nigricornis, in two field experiments conducted in a Washington hop yard. Significantly greater numbers of C. nigricornis were trapped on MeSA-baited sticky cards (mean: 2.8 +/- 0.4/card/week) than on unbaited cards (0.45 +/- 0.15) during June-September. Cards baited with two other HIPVs, hexenyl acetate and dimethyl nonatriene, did not attract more C. nigricornis than did unbaited traps (0.30 +/- 0.10, 0.44 +/- 0.15, respectively). MeSA-baited Unitraps captured 1.9 +/- 0.5 C. nigricornis/trap/week during July-August compared to 0.20 +/- 0.20/trap/week in methyl eugenol-baited traps and 0.03 +/- 0.03/trap/week in unbaited traps. The potential use of MeSA in enhancing C. nigricornis populations in Washington hop yards as an aid to conservation biological control of aphids and mites is discussed.

  13. Differential Response of a Local Population of Entomopathogenic Nematodes to Non-Native Herbivore Induced Plant Volatiles (HIPV) in the Laboratory and Field.

    Science.gov (United States)

    Rivera, Monique J; Rodriguez-Saona, Cesar; Alborn, Hans T; Koppenhöfer, Albrecht M

    2016-12-01

    Recent work has shown the potential for enhanced efficacy of entomopathogenic nematodes (EPN) through their attraction to herbivore induced plant volatiles. However, there has been little investigation into the utilization of these attractants in systems other than in those in which they were identified. We compared (E)-β-caryophyllene and pregeijerene in the highbush blueberry (Vaccinium corymbosum) agroecosystem in their ability to enhance the attraction of EPN to and efficacy against the system's herbivore, oriental beetle (Anomala orientalis). The relative attractiveness of (E)-β-caryophyllene and pregeijerene to a local isolate of the EPN species Steinernema glaseri was tested in a six-arm olfactometer in the laboratory to gather baseline values of attraction to the chemicals alone in sand substrate before field tests. A similar arrangement was used in a V. corymbosum field by placing six cages with assigned treatments and insect larvae with and without compound into the soil around the base of 10 plants. The cages were removed after 72 h, and insect baits were retrieved and assessed for EPN infection. The lab results indicate that in sand alone (E)-β-caryophyllene is significantly more attractive than pregeijerene to the local S. glaseri isolate Conversely, there was no difference in attractiveness in the field study, but rather, native S. glaseri were more attracted to cages with G. mellonella larvae, no larvae, and cages with the blank control and G. mellonella larvae.

  14. Nitrile hydrolysing activities of deep-sea and terrestrial mycolate actinomycetes.

    Science.gov (United States)

    Brandão, Pedro F B; Bull, Alan T

    2003-01-01

    Nitrile metabolising actinomycetes previously recovered from deep-sea sediments and terrestrial soils were investigated for their nitrile transforming properties. Metabolic profiling and activity assays confirmed that all strains catalysed the hydrolysis of nitriles by a nitrile hydratase/amidase system. Acetonitrile and benzonitrile, when used as growth substrates for enzyme induction experiments, had a significant influence on the biotransformation activities towards various nitriles and amides. The specific activities of selected deep-sea and terrestrial acetonitrile-grown bacteria against a suite of nitriles and amides were higher than those of the only other reported marine nitrile-hydrolysing R. erythropolis, isolated from a shallow sediment. The increase of nitrile chain length appeared to have negative influence on the nitrile hydratase activity of acetonitrile-grown bacteria, but the same was not true for benzonitrile-grown bacteria. The nitrile hydratases and amidases were constitutive in 10 of the 16 deep-sea and terrestrial actinomycetes studied, and one strain showed an inducible hydratase and a constitutive amidase. Most of the deep-sea strains had constitutive activities and showed some of the highest activities and broadest substrate specificities of organisms included in this study.

  15. Laboratory Evaluation of Nitrile Fuel Tank Materials (Phase 2)

    Science.gov (United States)

    2013-09-01

    reported skin temperatures that the tanks could experience in the SWA theater due to solar loading. Because no data was available at the start of this...environments, it is not unusual for skin temperatures to exceed 140 F. It becomes important and relevant to evaluate diffusion and strength...coating. A plasticizer is usually an oily type additive that allows the nitrile coating to remain flexible at low temperatures. It is well known that

  16. Molecular simulation of gas solubility in nitrile butadiene rubber

    OpenAIRE

    Khawaja, M.; Sutton, AP; Mostofi, AA

    2016-01-01

    Molecular simulation is used to compute the solubility of small gases in nitrile bu- tadiene rubber (NBR) with a Widom particle-insertion technique biased by local free volume. The convergence of the method is examined as a function of the number of snapshots upon which the insertions are performed and the number of insertions per snapshot, and is compared to the convergence of the unbiased Widom insertion technique. The effect of varying the definition of the local free volume is also invest...

  17. Catalyst-free synthesis of 3-sulfone nitrile from sulfonyl hydrazides and acrylonitrile in water.

    Science.gov (United States)

    Li, Wei; Gao, Lingfeng; Zhuge, Wenyun; Sun, Xu; Zheng, Gengxiu

    2017-09-26

    A novel catalyst-free sulfonation reaction for synthesizing 3-sulfone nitrile compounds from sulfonyl hydrazides and acrylonitriles in water, without any metal catalyst, ligand or organic solvent, was demonstrated. This catalyst-free protocol provides a new synthetic method for the construction of 3-sulfone nitrile compounds with excellent yields. The D2O experiment adequately proved that the catalyst-free sulfonation reaction occurs via a Michael addition mechanism and that the hydrogen of 3-sulfone nitrile comes from water.

  18. "Nanorust"-catalyzed benign oxidation of amines for selective synthesis of nitriles.

    Science.gov (United States)

    Jagadeesh, Rajenahally V; Junge, Henrik; Beller, Matthias

    2015-01-01

    Organic nitriles constitute key precursors and central intermediates in organic synthesis. In addition, nitriles represent a versatile motif found in numerous medicinally and biologically important compounds. Generally, these nitriles are synthesized by traditional cyanation procedures using toxic cyanides. Herein, we report the selective and environmentally benign oxidative conversion of primary amines for the synthesis of structurally diverse aromatic, aliphatic and heterocyclic nitriles using a reusable "nanorust" (nanoscale Fe2 O3 )-based catalysts applying molecular oxygen. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Ruthenium on chitosan: A recyclable heterogeneous catalyst for aqueous hydration of nitriles to amides

    Science.gov (United States)

    Ruthenium has been immobilized over chitosan by simply stirring an aqueous suspension of chitosan in water with ruthenium chloride and has been utilized for the oxidation of nitriles to amides; the hydration of nitriles occurs in high yield and excellent selectivity, which procee...

  20. Nitrile-converting enzymes: an eco-friendly tool for industrial biocatalysis.

    Science.gov (United States)

    Ramteke, Pramod W; Maurice, Navodita G; Joseph, Babu; Wadher, Bharat J

    2013-01-01

    Nitriles are organic compounds bearing a − C ≡ N group; they are frequently known to occur naturally in both fauna and flora and are also synthesized chemically. They have wide applicability in the fields of medicine, industry, and environmental monitoring. However, the majority of nitrile compounds are considered to be lethal, mutagenic, and carcinogenic in nature and are known to cause potential health problems such as nausea, bronchial irritation, respiratory distress, convulsions, coma, and skeletal deformities in humans. Nitrile-converting enzymes, which are extracted from microorganisms, are commonly termed nitrilases and have drawn the attention of researchers all over the world to combat the toxicity of nitrile compounds. The present review focuses on the utility of nitrile-converting enzymes, sources, classification, structure, properties, and applications, as well as the future perspective on nitrilases. © 2013 International Union of Biochemistry and Molecular Biology, Inc.

  1. Nitrile Hydratase and Amidase from Rhodococcus rhodochrous Hydrolyze Acrylic Fibers and Granular Polyacrylonitriles

    Science.gov (United States)

    Tauber, M. M.; Cavaco-Paulo, A.; Robra, K.-H.; Gübitz, G. M.

    2000-01-01

    Rhodococcus rhodochrous NCIMB 11216 produced nitrile hydratase (320 nkat mg of protein−1) and amidase activity (38.4 nkat mg of protein−1) when grown on a medium containing propionitrile. These enzymes were able to hydrolyze nitrile groups of both granular polyacrylonitriles (PAN) and acrylic fibers. Nitrile groups of PAN40 (molecular mass, 40 kDa) and PAN190 (molecular mass, 190 kDa) were converted into the corresponding carbonic acids to 1.8 and 1.0%, respectively. In contrast, surfacial nitrile groups of acrylic fibers were only converted to the corresponding amides. X-ray photoelectron spectroscopy analysis showed that 16% of the surfacial nitrile groups were hydrolyzed by the R. rhodochrous enzymes. Due to the enzymatic modification, the acrylic fibers became more hydrophilic and thus, adsorption of dyes was enhanced. This was indicated by a 15% increase in the staining level (K/S value) for C.I. Basic Blue 9. PMID:10742253

  2. Compatibilization efficiency of carboxylated nitrile rubber and epoxy pre-polymer in nitrile/acrylic rubber blends

    Directory of Open Access Journals (Sweden)

    Micheli L. Celestin

    2013-01-01

    Full Text Available An investigation has been made of the effects from a compatibilizer, viz. carboxylated nitrile rubber (XNBR, on several properties of nitrile rubber (NBR and acrylic rubber (ACM blends, including curing characteristics, mechanical, dynamic mechanical and dielectric properties. The presence of XNBR until 10 phr resulted in an improvement of the ultimate tensile properties, especially elongation at break. The mechanical properties associated to the volume fraction of rubber in the network (Vr and torque values suggest the co-vulcanization phenomenon imparted by the compatibilization. The oil resistance of NBR/ACM (50:50 wt. (% blends (compatibilized and non compatibilized was similar to that observed for pure ACM and significantly higher than NBR. The addition of small amounts of epoxy pre-polymer in combination with XNBR resulted in an additional improvement of the tensile properties. The dynamic mechanical and dielectric properties of the blends were also investigated. The loss modulus values of the compatibilized blends were significantly lower indicating an increase of the elastic characteristics. All blends presented two dielectric relaxation peaks confirming the heterogeneity of the compatibilized blends

  3. Nitrile O-ring Cracking: A Case of Vacuum Flange O-ring Failures

    Energy Technology Data Exchange (ETDEWEB)

    Dees, Craig

    2016-07-01

    A review of recent nitrile O-ring failures in ISO-KF vacuum flange connections in glovebox applications is presented. An investigation of a single “isolated” o-ring failure leads to the discovery of cracked nitrile o-rings in a glovebox atmospheric control unit. The initial cause of the o-ring failure is attributed to ozone degradation. However, additional investigation reveals nitrile o-ring cracking on multiple gloveboxes and general purpose piping, roughly 85% of the nitrile o-rings removed for inspection show evidence of visible cracking after being in service for 18 months or less. The results of material testing and ambient air testing is presented, elevated ozone levels are not found. The contributing factors of o-ring failure, including nitrile air sensitivity, inadequate storage practices, and poor installation techniques, are discussed. A discussion of nitrile o-ring material properties, the benefits and limitations, and alternate materials are discussed. Considerations for o-ring material selection, purchasing, storage, and installation are presented in the context of lessons learned from the nitrile o-ring cracking investigation. This paper can be presented in 20 minutes and does not require special accommodations or special audio visual devices.

  4. Nucleophilic addition of nitriles to secondary terpene alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, N.G.; Popova, L.A.; Nesterov, G.V.

    1987-01-10

    The addition of nitriles of varying nucleophilicity to isocamphanol and exo-1,5,5-trimethyl-bicyclo(2.2.1)heptan-2-ol (isofenchol) was investigated. The authors examined the effect of the reaction conditions on the yield and structure of the target products of the reaction: N-substituted amides. As a result of the study, it was shown that in the reaction with chloroacetonitrile, propionitrile, methoxypropionitrile, isovaleronitrile, and phenylacetonitrile under the conditions of the Ritter reaction, isocamphanol is transformed into the corresponding substituted exo-N-acyl-1,7,7-trimethylbicyclo(2.2.1)hept-2-ylamines, as in the reaction with aceto- and benzonitriles, due to 2,6-hydride displacement accompanied by Wagner-Meerwein rearrangement. The structures of these amides were demonstrated by PMR spectroscopy.

  5. Carboxylated nitrile butadiene rubber/hybrid filler composites

    Directory of Open Access Journals (Sweden)

    Ahmad Mousa

    2012-08-01

    Full Text Available The surface properties of the OSW and NLS are measured with the dynamic contact-angle technique. The x-ray photoelectron spectroscopy (XPS of the OSW reveals that the OSW possesses various reactive functional groups namely hydroxyl groups (OH. Hybrid filler from NLS and OSW were incorporated into carboxylated nitrile rubber (XNBR to produce XNBR hybrid composites. The reaction of OH groups from the OSW with COOH of the XNBR is checked by attenuated total reflectance spectra (ATR-IR of the composites. The degree of curing ΔM (maximum torque-minimum torque as a function of hybrid filler as derived from moving die rheometer (MDR is reported. The stress-strain behavior of the hybrid composites as well as the dynamic mechanical thermal analysis (DMTA is studied. Bonding quality and dispersion of the hybrid filler with and in XNBR are examined using scanning-transmission electron microscopy (STEM in SEM.

  6. Macromolecular surface design: photopatterning of functional stable nitrile oxides.

    Science.gov (United States)

    Altintas, Ozcan; Glassner, Mathias; Rodriguez-Emmenegger, Cesar; Welle, Alexander; Trouillet, Vanessa; Barner-Kowollik, Christopher

    2015-05-04

    The efficient trapping of photogenerated thioaldehydes with functional shelf-stable nitrile oxides in a 1,3-dipolar cycloaddition is a novel and versatile photochemical strategy for polymer end-group functionalization and surface modification under mild and equimolar conditions. The modular ligation in solution was followed in detail by electrospray ionization mass spectrometry (ESI-MS). X-ray photoelectron spectroscopy (XPS) was employed to analyze the functionalized surfaces, whereas time-of-flight secondary-ion mass spectrometry (ToF-SIMS) confirmed the spatial control of the surface functionalization using a micropatterned shadow mask. Polymer brushes were grown from the surface in a spatially confined regime by surface-initiated atom transfer radical polymerization (SI-ATRP) as confirmed by TOF-SIMS, XPS as well as ellipsometry. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Visible-light photolytic synthesis of multinuclear and dendritic iron-nitrile cationic complexes.

    Science.gov (United States)

    Ornelas, Cátia; Ruiz, Jaime; Rodrigues, João; Astruc, Didier

    2008-05-19

    Multinuclear and dendritic iron-nitrile piano-stool cationic complexes were synthesized in quantitative yield by a single-step synthesis involving visible-light photolysis of the complex [CpFe(eta(6)-toluene)][PF6]. This synthetic strategy was applied to mono-, bis- and tris-nitrile ligands and to new nitrile-terminated dendrimers containing 9, 27, and 81 tethers. All the synthesized products are deep red solids or red waxy products, highly stable to air and moisture. They were characterized by (1)H, (13)C, and (31)P NMR, elemental analysis, UV-vis spectroscopy, and cyclic voltammetry (single reversible oxidation wave to Fe(III)). Only the para-disubstituted arene dinitrile diiron complex shows two separated reversible waves indicating some electronic communication between the iron centers through the nitrile ligands.

  8. Changes in chemical permeation of disposable latex, nitrile, and vinyl gloves exposed to simulated movement.

    Science.gov (United States)

    Phalen, Robert N; Le, Thi; Wong, Weng Kee

    2014-01-01

    Glove movement can affect chemical permeation of organic compounds through polymer glove products. However, conflicting reports make it difficult to compare the effects of movement on chemical permeation through commonly available glove types. The aim of this study was to evaluate the effect of movement on chemical permeation of an organic solvent through disposable latex, nitrile, and vinyl gloves. Simulated whole-glove permeation testing was conducted using ethyl alcohol and a previously designed permeation test system. With exposure to movement, a significant decrease (p ≤ 0.001) in breakthrough time (BT) was observed for the latex (-23%) and nitrile gloves (-31%). With exposure to movement, only the nitrile glove exhibited a significant increase (p ≤ 0.001) in steady-state permeation rate (+47%) and cumulative permeation at 30 min (+111%). Even though the nitrile glove provided optimum chemical resistance against ethyl alcohol, it was most affected by movement. With exposure to movement, the latex glove was an equivalent option for overall worker protection, because it was less affected by movement and the permeation rate was lower than that of the nitrile glove. In contrast, the vinyl glove was the least affected by movement, but did not provide adequate chemical resistance to ethyl alcohol in comparison with the nitrile and latex gloves. Glove selection should take movement and polymer type into account. Some glove polymer types are less affected by movement, most notably the latex glove in this test. With nitrile gloves, at least a factor of three should be used when attempting to assign a protection factor when repetitive hand motions are anticipated. Ultimately, the latex gloves outperformed nitrile and vinyl in these tests, which evaluated the effect of movement on chemical permeation. Future research should aim to resolve some of the observed discrepancies in test results with latex and vinyl gloves.

  9. Molecular Simulation of Gas Solubility in Nitrile Butadiene Rubber.

    Science.gov (United States)

    Khawaja, M; Sutton, A P; Mostofi, A A

    2017-01-12

    Molecular simulation is used to compute the solubility of small gases in nitrile butadiene rubber (NBR) with a Widom particle-insertion technique biased by local free volume. The convergence of the method is examined as a function of the number of snapshots upon which the insertions are performed and the number of insertions per snapshot and is compared to the convergence of the unbiased Widom insertion technique. The effect of varying the definition of local free volume is also investigated. The acrylonitrile content of the polymer is altered to examine its influence on the solubility of helium, CO2, and H2O, and the solubilities of polar gases are found to be enhanced relative to those of nonpolar gases, in qualitative agreement with experiment. To probe this phenomenon further, the solubilities are decomposed into contributions from the neighborhoods of different atoms, using a Voronoi cell construction, and a strong bias is found for CO2 and H2O in particular to be situated near nitrogen sites in the elastomer. Temperature is shown to suppress the solubility of CO2 and H2O but to increase that of helium. Increasing pressure is found to suppress the solubility of all gases but at different rates, according to a balance between their molecular sizes and electrostatic interactions with the polymer. These results are relevant to the use of NBR seals at elevated temperatures and pressures, such as in oil and gas wells.

  10. Reactions of diiron m-aminocarbyne complexes containing nitrile ligands

    Directory of Open Access Journals (Sweden)

    Busetto Luigi

    2003-01-01

    Full Text Available The acetonitrile ligand in the mu-aminocarbyne complexes [Fe2{mu-CN(MeR}(mu-CO(CO(NCMe(Cp2][SO 3CF3] (R = Me, 2a, CH2Ph, 2b, Xyl, 2c (Xyl = 2,6-Me2C6H3 is readily displaced by halides and cyanide anions affording the corresponding neutral species [Fe2{mu-CN(MeR}(mu-CO(CO(X(Cp2 ] (X = Br, I, CN. Complexes 2 undergo deprotonation and rearrangement of the coordinated MeCN upon treatment with organolithium reagents. Trimethylacetonitrile, that does not contain acidic alpha hydrogens has been used in place of MeCN to form the complexes [Fe2{mu-CN(MeR}(mu-CO(CO(NCCMe3 (Cp2][SO3CF3] (7a-c. Attempts to replace the nitrile ligand in 3 with carbon nucleophiles (by reaction with RLi failed, resulting in decomposition products. However the reaction of 7c with LiCºCTol (Tol = C6H4Me, followed by treatment with HSO3CF3, yielded the imino complex [Fe2{mu-CN(MeXyl}(mu-CO(CO {N(HC(CºCC6H4Me-4CMe3}(Cp 2][SO3CF3 ] (8, obtained via acetilyde addition at the coordinated NCCMe3.

  11. Reinforcement of nitrile rubber by in situ formed zinc disorbate

    Directory of Open Access Journals (Sweden)

    2010-09-01

    Full Text Available Zinc disorbate (ZDS was in situ formed by the reaction between sorbic acid (SA and zinc oxide (ZnO in nitrile rubber (NBR. The effects of SA amount on the curing characteristics, crosslink density and mechanical properties of peroxide- cured NBR were studied. The results showed that ZDS was generated mainly during the rubber vulcanization, rather than the open mill compounding phase. The results from the crosslink density determinations showed that the formation of ZDS significantly increased the ionic bond content in the vulcanizates. In addition, the formation of ZDS greatly enhanced the mechanical properties of NBR vulcanizates. The modulus, tensile strength, tear strength and hardness were found to be increased with the loading of ZDS. Preheating the compounds before compression moulding was beneficial to the formation of ZDS, and consequently the increases in mechanical properties. At 40 parts per hundred rubber (phr of SA and 16 phr ZnO, five to six folds of tensile strength and tear strength of the neat NBR vulcanizate were achieved. Transmission electron microscopy (TEM results confirmed the nano-dispersion structure of the polymerized ZDS in the NBR matrix.

  12. Correlating Nitrile IR Frequencies to Local Electrostatics Quantifies Noncovalent Interactions of Peptides and Proteins.

    Science.gov (United States)

    Deb, Pranab; Haldar, Tapas; Kashid, Somnath M; Banerjee, Subhrashis; Chakrabarty, Suman; Bagchi, Sayan

    2016-05-05

    Noncovalent interactions, in particular the hydrogen bonds and nonspecific long-range electrostatic interactions are fundamental to biomolecular functions. A molecular understanding of the local electrostatic environment, consistently for both specific (hydrogen-bonding) and nonspecific electrostatic (local polarity) interactions, is essential for a detailed understanding of these processes. Vibrational Stark Effect (VSE) has proven to be an extremely useful method to measure the local electric field using infrared spectroscopy of carbonyl and nitrile based probes. The nitrile chemical group would be an ideal choice because of its absorption in an infrared spectral window transparent to biomolecules, ease of site-specific incorporation into proteins, and common occurrence as a substituent in various drug molecules. However, the inability of VSE to describe the dependence of IR frequency on electric field for hydrogen-bonded nitriles to date has severely limited nitrile's utility to probe the noncovalent interactions. In this work, using infrared spectroscopy and atomistic molecular dynamics simulations, we have reported for the first time a linear correlation between nitrile frequencies and electric fields in a wide range of hydrogen-bonding environments that may bridge the existing gap between VSE and H-bonding interactions. We have demonstrated the robustness of this field-frequency correlation for both aromatic nitriles and sulfur-based nitriles in a wide range of molecules of varying size and compactness, including small molecules in complex solvation environments, an amino acid, disordered peptides, and structured proteins. This correlation, when coupled to VSE, can be used to quantify noncovalent interactions, specific or nonspecific, in a consistent manner.

  13. Differing mechanisms of simple nitrile formation on glucosinolate degradation in Lepidium sativum and Nasturtium officinale seeds.

    Science.gov (United States)

    Williams, David J; Critchley, Christa; Pun, Sharon; Chaliha, Mridusmita; O'Hare, Timothy J

    2009-01-01

    Glucosinolates are sulphur-containing glycosides found in brassicaceous plants that can be hydrolysed enzymatically by plant myrosinase or non-enzymatically to form primarily isothiocyanates and/or simple nitriles. From a human health perspective, isothiocyanates are quite important because they are major inducers of carcinogen-detoxifying enzymes. Two of the most potent inducers are benzyl isothiocyanate (BITC) present in garden cress (Lepidium sativum), and phenylethyl isothiocyanate (PEITC) present in watercress (Nasturtium officinale). Previous studies on these salad crops have indicated that significant amounts of simple nitriles are produced at the expense of the isothiocyanates. These studies also suggested that nitrile formation may occur by different pathways: (1) under the control of specifier protein in garden cress and (2) by an unspecified, non-enzymatic path in watercress. In an effort to understand more about the mechanisms involved in simple nitrile formation in these species, we analysed their seeds for specifier protein and myrosinase activities, endogenous iron content and glucosinolate degradation products after addition of different iron species, specific chelators and various heat treatments. We confirmed that simple nitrile formation was predominantly under specifier protein control (thiocyanate-forming protein) in garden cress seeds. Limited thermal degradation of the major glucosinolate, glucotropaeolin (benzyl glucosinolate), occurred when seed material was heated to >120 degrees C. In the watercress seeds, however, we show for the first time that gluconasturtiin (phenylethyl glucosinolate) undergoes a non-enzymatic, iron-dependent degradation to a simple nitrile. On heating the seeds to 120 degrees C or greater, thermal degradation of this heat-labile glucosinolate increased simple nitrile levels many fold.

  14. Comparative investigations of genotoxic activity of five nitriles in the comet assay and the Ames test.

    Science.gov (United States)

    Wu, Jong-C; Hseu, You C; Chen, Chin-H; Wang, Shu-H; Chen, Ssu C

    2009-09-30

    Two short-term assays, the modified Ames test and the comet assay, were carried out to evaluate the genotoxicity of five nitriles (acetonitrile, propionitrile, methacrylonitrile, butyronitrile, and benzonitrile). With the comet assay, all the nitriles studied were found to induce the genotoxicity in human lymphocytes and Hep G2 cells. Except for butyronitrile, the genotoxic potency in lymphocytes was more pronounced than that in Hep G2 cells, and the rank order of genotoxicity induced by these five nitriles in lymphocytes was different from that in Hep G2 cells, indicating that the pathways leading to genotoxicity in both types of cells were different. In the modified Ames test, no tested nitriles showed mutagenic activity on Salmonella typhimurium strain TA 98 and TA 100 with and without metabolic activation. Comparing the results obtained from both tests in this study, the comet assay seems to be more sensitive than the modified Ames test. Thus, the comet assay can be used to detect the genotoxicity of all nitriles.

  15. Nitrile-functionalized tertiary amines as highly efficient and reversible SO{sub 2} absorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Yun; Kim, Heehwan; Kim, Young Jin; Jeong, Junkyo; Cheong, Minserk [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Hyunjoo [Clean Energy Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Kim, Hoon Sik, E-mail: khs2004@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Lee, Je Seung, E-mail: leejs70@khu.ac.kr [Department of Chemistry and Research Institute of Basic Sciences, Kyung Hee University, 1 Hoegi-dong, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2014-01-15

    Highlights: • Nitrile-functionalized tertiary amines physically and reversibly absorb SO{sub 2}. • Tertiary alkanolamines chemically and irreversibly absorb SO{sub 2} through OH group. • SO{sub 2} absorption modes were studied by spectroscopy and computational calculations. -- Abstract: Three different types of nitrile-functionalized amines, including 3-(N,N-diethylamino)propionitrile (DEAPN), 3-(N,N-dibutylamino)propionitrile (DBAPN), and N-methyl-N,N-dipropionitrile amine (MADPN) were synthesized, and their SO{sub 2} absorption performances were evaluated and compared with those of hydroxy-functionalized amines such as N,N-diethyl-N-ethanol amine (DEEA), N,N-dibutyl-N-ethanol amine (DBEA), and N-methyl-N,N-diethanol amine (MDEA). Absorption–desorption cycle experiments clearly demonstrate that the nitrile-functionalized amines are more efficient than the hydroxy-functionalized amines in terms of absorption rate and regenerability. Computational calculations with DBEA and DBAPN revealed that DBEA bearing a hydroxyethyl group chemically interacts with SO{sub 2} through oxygen atom, forming an ionic compound with a covalently bound -OSO{sub 2}{sup −} group. On the contrary, DBAPN bearing a nitrile group physically interacts with SO{sub 2} through the nitrogen and the hydrogen atoms of the two methylene groups adjacent to the amino and nitrile functionalities.

  16. Chemistry of nitrile anions in the interstellar medium

    Energy Technology Data Exchange (ETDEWEB)

    Carles, S.; Le Garrec, J.-L.; Biennier, L. [Institut de Physique de Rennes, Département de Physique Moléculaire, Astrophysique de Laboratoire, UMR CNRS 6251, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex (France); Guillemin, J.-C. [Institut des Sciences Chimiques de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837,35708 Rennes Cedex 7 (France)

    2015-12-31

    Despite the extreme conditions of temperature (down to 10K) and density (down to 100 molecules/cm{sup 3}), the giant molecular clouds and the circumstellar envelopes present a rich and complex chemistry. To date, more than 180 molecules have been detected in the InterStellar Medium (ISM) with a large abundance of nitriles (RC≡N). In addition, several anions have been recently observed in this medium: C{sub 4}H{sup ¯}, C{sub 6}H{sup ¯}, C{sub 8}H{sup ¯}, CN{sup ¯}, C{sub 3}N{sup ¯} and C{sub 5}N{sup ¯}. These last species should play a key role in the molecular growth towards complexity. To explore this hypothesis, their reactivity must be studied in the laboratory. The FALP-MS and the CRESU experimental apparatuses of the Rennes University are able to measure absolute rate coefficient of various chemical reactions, including the ion – molecule reactions, in gas phase at low temperature (from 300K for the FALP-MS down to 15K for the CRESU). Therefore, these experimental tools are particularly adapted to the kinetic studies of reactions potentially involved in the Interstellar Medium. One of the difficulties encountered in experiments with anions is their generation. We describe here the formation of the CN{sup ¯} and C{sub 3}N{sup ¯} anions by dissociative electron attachment on the molecular precursors BrCN and BrC{sub 3}N.

  17. Reactivity of the geminal phosphinoborane tBu2PCH2BPh2 towards alkynes, nitriles, and nitrilium triflates

    NARCIS (Netherlands)

    Habraken, Evi R. M.; Mens, Lars C.; Nieger, Martin; Lutz, Martin; Ehlers, Andreas W.; Slootweg, J. Chris

    2017-01-01

    The reactivity of the geminal phosphinoborane tBu2PCH2BPh2 towards terminal alkynes, nitriles and nitrilium salts is investigated. Terminal alkynes react via C–H bond splitting (deprotonation) resulting in the formation of phosphonium borates. In contrast, both nitriles and nitrilium salts undergo

  18. Investigation of the reaction of α-Thioamides, α-esters and α–nitriles with N-halosuccinimides

    OpenAIRE

    Kissane, Marie; Murphy, Maureen; Lynch, Denis; Ford, Alan; Maguire, Anita R

    2008-01-01

    Investigation of the reaction of α-thioamides, α-esters and α-nitriles with NBS and NCS is described. The scope of this stereoselective oxidative transformation to the β- haloacrylamides, β-acrylates and β–acrylonitriles has been determined. A mechanistic rationale to explain the observed differences in reactivity between the amide, ester and nitrile series is proposed.

  19. Rhodium-catalyzed enantioselective hydrogenation of α-amino acrylonitriles: an efficient approach to synthesizing chiral α-amino nitriles.

    Science.gov (United States)

    Li, Xiuxiu; You, Cai; Yang, Yusheng; Wang, Fangyuan; Li, Shuailong; Lv, Hui; Zhang, Xumu

    2017-01-19

    An efficient rhodium-catalyzed asymmetric hydrogenation of α-amino acrylonitriles has been developed, affording α-acylamino nitriles with high yields and excellent enantioselectivities (up to 99% yield and >99% ee). This novel methodology provides an efficient and concise synthetic route to chiral α-amino nitriles, which are versatile intermediates in organic synthesis.

  20. Ammoniation-dehydration of fatty acids into nitriles: heterogeneous or homogeneous catalysis?

    Science.gov (United States)

    Mekki-Berrada, Adrien; Bennici, Simona; Gillet, Jean-Philippe; Couturier, Jean-Luc; Dubois, Jean-Luc; Auroux, Aline

    2013-08-01

    Fatty nitriles have lately become of interest in the framework of biofuels and for the valorization of the oil part of biomass to form fine chemicals or polymers. The production of long-chain fatty nitriles by the direct reaction of acids with NH3 has not been extensively studied, although several catalysts have been developed and published as patents. The characterization of this reaction with and without catalyst is, to the best of our knowledge, performed for the first time in this study. Several catalysts with various acid-base features were tested, and the best catalysts at 250 °C (Zn- and In-based catalysts) were further studied. Catalytically active forms and models are proposed for the Zn- and In-based catalysts, and the kinetic parameters for the amide to nitrile reaction are evaluated. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Model fire tests on polyphosphazene rubber and polyvinyl chloride (PVC)/nitrile rubber foams

    Science.gov (United States)

    Widenor, W. M.

    1978-01-01

    A video tape record of model room fire tests was shown, comparing polyphosphazene (P-N) rubber and polyvinyl chloride (PVC)/nitrile rubber closed-cell foams as interior finish thermal insulation under conditions directly translatable to an actual fire situation. Flashover did not occur with the P-N foam and only moderate amounts of low density smoke were formed, whereas with the PVC/nitrile foam, flashover occurred quickly and large volumes of high density smoke were emitted. The P-N foam was produced in a pilot plant under carefully controlled conditions. The PVC/nitrile foam was a commercial product. A major phase of the overall program involved fire tests on P-N open-cell foam cushioning.

  2. [Transformation of 2- and 4-cyanopyridines by free and immobilized cells of nitrile-hydrolyzing bacteria].

    Science.gov (United States)

    Maksimova, Iu G; Vasil'ev, D M; Ovechkina, G V; Maksimov, A Iu; Demakov, V A

    2013-01-01

    The transformation dynamics of 2- and 4-cyanopyridines by cells suspended and adsorbed on inorganic carriers has been studied in the Rhodococcus ruber gt 1 strain possessing nitrile hydratase activity and the Pseudomonas fluorescens C2 strain containing nitrilase. It was shown that both nitrile hydratase and nitrilase activities of immobilized cells against 2-cyanopyridine were 1.5-4 times lower compared to 4-cyanopyridine and 1.6-2 times lower than the activities of free cells against 2-cyanpopyridine. The possibility of obtaining isonicotinic acid during the combined conversion of 4-cyanopyridine by a mixed suspension of R. ruber gt 1 cells with a high level of nitrile hydratase activity and R. erythropolis 11-2 cells with a pronounced activity of amidase has been shown. Immobilization of Rhodococcus cells on raw coal and Pseudomonas cells on china clay was shown to yield a heterogeneous biocatalyst for the efficient transformation of cyanopyridines into respective amides and carbonic acids.

  3. The swelling of nitrile rubber by selected species in a synthetic jet turbine fuel

    Science.gov (United States)

    Graham, John Lynn

    The swelling of nitrile O-ring seals in petroleum distillate fuels has long been attributed to the aromatic species in these fuels. This presents a problem for synthetic fuels as they typically do not contain these aromatic species and thus may cause O-ring seals to shrink and fail. The composition of petroleum distillate fuels is extremely complex and it is not clear whether the swelling property originates from the aromatics in general, or if certain aromatics contribute more swelling character than others. Consequently, developing a general description of an efficient swelling promoter for O-rings in liquid hydrocarbon fuels will allow an unambiguous selection of candidate swelling agents for synthetic fuels. To accomplish this, a study was undertaken of the swelling of nitrile rubber (the most widely used O-ring material) in JP-5 (the jet propulsion fuel used by the U.S. Navy) and its synthetic equivalent S-5. Briefly, examining the molecular structure of nitrile rubber showed the fuel resistance of this polymer resides in the polar character of the cyano group suggesting that polar species in general, and hydrogen-bonded species in particular, should serve as efficient swelling promoters. A thorough test program utilizing a unique optical dilatometry method to provide temporal volume swell data, a GC-MS method for measuring the polymer/fuel partitioning, and a spectroscopic examination of thin nitrile rubber films confirmed this hypothesis. This program also showed that swelling character increases with decreasing molar volume which is consistent with previous work and general theories of solubility. Overall, this study showed that the most efficient aromatic swelling promoters for nitrile rubber are naphthalenes and asymmetrically substituted alkyl benzenes. However, polar species such as ketones and alcohols can be more efficient than aromatics while phenols and aromatic alcohols represent the most efficient potential swelling promoters for nitrile rubber in

  4. Mechanistic insights into the oxidative dehydrogenation of amines to nitriles in continuous flow

    DEFF Research Database (Denmark)

    Corker, Emily C.; Ruiz-Martínez, Javier; Riisager, Anders

    2015-01-01

    and the amine utilised. The presence of water was found to be important for the activity and stability of the RuO2/Al2O3 catalyst. The Hammett relationship and in situ infrared spectroscopy were applied to divulge details about the catalytic mechanism of the oxidative dehydrogenation of amines over RuO2/Al2O3......The oxidative dehydrogenation of various aliphatic amines to their corresponding nitrile compounds using RuO2/Al2O3 catalysts in air was successfully applied to a continuous flow reaction. Conversions of amines (up to >99%) and yields of nitriles (up to 77%) varied depending on reaction conditions...

  5. Ruthenium hydroxide supported on magnetic nanoparticles: a benign aqueous protocol for hydration of nitriles

    Science.gov (United States)

    Amides are an important class of compounds in the chemical and pharmaceutical industry1,2. Conventionally, amides have been synthesized by the hydration of nitriles, catalyzed by strong acids3 and bases4. Many by-products such as carboxylic acids are produced due to hydrolysis of...

  6. Total synthesis of the sesquiterpene (+/-)-illudin C via an intramolecular nitrile oxide cycloaddition.

    Science.gov (United States)

    Aungst, R A; Chan, C; Funk, R L

    2001-08-09

    [reaction: see text] A convergent total synthesis of illudin C is described. The tricyclic ring system of the natural product was quickly assembled from cyclopropane and cyclopentene precursors via a novel oxime dianion coupling reaction and a subsequent intramolecular nitrile oxide-olefin cycloaddition.

  7. Copper-mediated pyrazole synthesis from 2,3-allenoates or 2-alkynoates, amines and nitriles.

    Science.gov (United States)

    Chen, Bo; Zhu, Can; Tang, Yang; Ma, Shengming

    2014-07-21

    An efficient copper-mediated three-component reaction of 2,3-allenoates or 2-alkynoates, amines, and nitriles affording fully substituted pyrazoles with a very nice diversity has been developed. A tandem conjugate addition, 1,2-addition, and N-N bond formation mechanism has been proposed for this diverse synthesis of pyrazoles based on mechanistic studies.

  8. Direct N-acetyl enamine formation: lithium bromide mediated addition of methyllithium to nitriles.

    Science.gov (United States)

    Savarin, Cécile G; Boice, Geneviève N; Murry, Jerry A; Corley, Edward; DiMichele, Lisa; Hughes, Dave

    2006-08-31

    An improved protocol for N-acetyl enamine formation is disclosed which involves LiBr-mediated addition of MeLi to substituted nitriles. The resulting enamides are isolated in high yields and excellent purity which permits subsequent hydrogenation at very low catalyst loading.

  9. Esp-independent biofilm formation by Enterococcus faecalis.

    Science.gov (United States)

    Kristich, Christopher J; Li, Yung-Hua; Cvitkovitch, Dennis G; Dunny, Gary M

    2004-01-01

    Enterococcus faecalis is a gram-positive opportunistic pathogen known to form biofilms in vitro. In addition, this organism is often isolated from biofilms on the surfaces of various indwelling medical devices. However, the molecular mechanisms regulating biofilm formation in these clinical isolates are largely unknown. Recent work has suggested that a specific cell surface protein (Esp) of E. faecalis is critical for biofilm formation by this organism. However, in the same study, esp-deficient strains of E. faecalis were found to be capable of biofilm formation. To test the hypothesis that Esp is dispensable for biofilm formation by E. faecalis, we used microtiter plate assays and a chemostat-based biofilm fermentor assay to examine biofilm formation by genetically well-defined, non-Esp-expressing strains. Our results demonstrate that in vitro biofilm formation occurs, not only in the absence of esp, but also in the absence of the entire pathogenicity island that harbors the esp coding sequence. Using scanning electron microscopy to evaluate biofilms of E. faecalis OG1RF grown in the fermentor system, biofilm development was observed to progress through multiple stages, including attachment of individual cells to the substratum, microcolony formation, and maturation into complex multilayered structures apparently containing water channels. Microtiter plate biofilm analyses indicated that biofilm formation or maintenance was modulated by environmental conditions. Furthermore, our results demonstrate that expression of a secreted metalloprotease, GelE, enhances biofilm formation by E. faecalis. In summary, E. faecalis forms complex biofilms by a process that is sensitive to environmental conditions and does not require the Esp surface protein.

  10. Quantum chemical study of relative reactivities of a series of amines and nitriles - Relevance to prebiotic chemistry

    Science.gov (United States)

    Loew, G. H.; Berkowitz, D.; Chang, S.

    1975-01-01

    Using the Iterative Extended Huckel Theory (IEHT) calculations of the electron distribution and orbital energies of a series of thirteen amines, nitriles and amino-nitriles relevant to prebiotic and cosmo-chemistry have been carried out. Ground state properties such as the energy and nature of the highest occupied (HOMO) and lowest empty (LEMO) molecular orbitals, net atomic charges and number of nonbonding electrons have been identified as criteria for correlating the relative nucleophilicity of amine and nitrile nitrogens and the electrophilicity of nitrile and other unsaturated carbon atoms. The results of such correlations can be partially verified by known chemical behavior of these compounds and are used to predict and understand their role in prebiotic organic synthesis.

  11. Ruthenium-catalyzed aerobic oxidative decarboxylation of amino acids: a green, zero-waste route to biobased nitriles.

    Science.gov (United States)

    Claes, Laurens; Verduyckt, Jasper; Stassen, Ivo; Lagrain, Bert; De Vos, Dirk E

    2015-04-18

    Oxidative decarboxylation of amino acids into nitriles was performed using molecular oxygen as terminal oxidant and a heterogeneous ruthenium hydroxide-based catalyst. A range of amino acids was oxidized in very good yield, using water as the solvent.

  12. Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Likozar, Blaz, E-mail: blaz.likozar@fkkt.uni-lj.si [Polymer Competence Center Leoben GmbH, Montanuniversitaet Leoben, Roseggerstrasse 12, A-8700 Leoben (Austria); Major, Zoltan, E-mail: zoltan.major@jku.at [Polymer Competence Center Leoben GmbH, Montanuniversitaet Leoben, Roseggerstrasse 12, A-8700 Leoben (Austria)

    2010-11-01

    The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 x 10{sup 28} m{sup -3}), density (maximally 1.16 g cm{sup -3}), and tear strength (11.2 kN m{sup -1}), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

  13. Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

    Science.gov (United States)

    Likozar, Blaž; Major, Zoltan

    2010-11-01

    The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 × 1028 m-3), density (maximally 1.16 g cm-3), and tear strength (11.2 kN m-1), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

  14. An Efficient Synthesis of Nitriles from Aldoximes Using Diethyl Phosphorocyanidate under Mild Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kieseung; An, Hyeonseong; Hwang, Chanyeon [Woosuk Univ.,Wanju (Korea, Republic of)

    2012-10-15

    Nitriles are valuable intermediates in organic synthesis not only because they serve as the appropriate precursors to various functional groups, but also because they are widely used as the key intermediates for pharmaceuticals, agrochemicals and various N-heterocyclic compounds. The cyano group itself is also frequently found in many biologically important molecules. Therefore, a variety of synthetic routes to nitriles from diverse chemical precursors have been developed. Among these routes, nitrile synthesis from aldoximes using an appropriate dehydrating agent has been a general and clean method. For this purpose, numerous reagents such as chlorosulfonyl isocyanate, di-2-pyridyl sulfite, Burgess reagent, [RuCl{sub 2}(p-cymene)]{sub 2}/MS, 4A, BOP, Pd(OAc){sub 2}/PPh{sub 3}, Cu(OAc){sub 2}/ultrasound have been developed. These reagents, however, may have limitations in some respects such as harsh reaction conditions, use of expensive or less readily available reagents, low yields, and lack of generality. Therefore, there is still a need to develop mild and general method for this conversion. Diethyl phosphorocyanidate (DEPC) was initially introduced as an efficient peptide coupling reagent, and has been utilized for useful organic reactions. Previously, we reported that 2-chloro-1-methylpyridinium iodide is an efficient and mild reagent for the dehydration of aldoximes to nitriles under mild conditions. In continuation of our interest in developing mild method for the conversion of aldoximes to nitriles, we herein wish to report the first application of DEPC to the efficient synthesis of nitriles from aldoximes under mild conditions (Scheme 1). In order to obtain the information regarding the optimum reaction conditions, 4-pyridine aldoxime (1a) was reacted with DEPC without base, and in presence of various base in CH{sub 2}Cl{sub 2} at rt for a prolonged reaction time (20 h) (Table 1). CH{sub 2}CI{sub 2} was chosen as reaction medium in this reaction due to the

  15. The effect of zinc oxide nanoparticle morphology on activity in crosslinking of carboxylated nitrile elastomer

    Directory of Open Access Journals (Sweden)

    2009-09-01

    Full Text Available The aim of this work was to study the activity of several nanosized zinc oxides in the crosslinking of carboxylated nitrile elastomer (XNBR. In this article, we discuss the effect of zinc oxide nanoparticles with respect to their specific surface area, particle size and morphology (spheres, whiskers, and snowflakes on the crosslinking density and mechanical properties of vulcanisates. The morphology of nanoparticles considerably influences the activity of zinc oxide towards carboxylated nitrile rubber. As a crosslinking agent, zinc oxide with snowflake particles seems to be the most active. The application of nanosized zinc oxide allows the amount of ZnO to be reduced by almost 40%, as compared to vulcanisates containing microsized particles. Moreover, vulcanisates crosslinked with zinc oxide nanoparticles exhibit thermoplastic properties that enable this material to be recycled, which is very important from an ecological point of view.

  16. NMR studies on 1,3-dipolar cycloaddition of nitrile oxides to norbornenes

    Energy Technology Data Exchange (ETDEWEB)

    Gucma, Miroslaw; Golebiewski, W. Marek; Krawczyk, Maria, E-mail: golebiewski@ipo.waw.pl [Institute of Industrial Organic Chemistry, Warsaw (Poland)

    2013-05-15

    The 1,3-dipolar cycloaddition reaction of nitrile oxides to norbornenes substituted with an acrylate-derived moiety was examined. Only adducts to norbornene system were formed with a good exo selectivity and complete site-selectivity. Structures of the products were elucidated by an extensive application of electrospray ionization-mass spectrometry (ESI-MS) and 2D {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR). (author)

  17. Permeability test and fuzzy orthogonal analysis of hydrogenated nitrile O-ring

    OpenAIRE

    Hu, Qin; Wan, Changcheng; Wang, Changxin

    2015-01-01

    In the high temperature, high pressure and high corrosive environment of the oil and gas drilling downhole, the weatherability of rubber sealing material has a great influence on the production safety. In order to study the important degree of every key environmental factor in downhole influencing the sealing performance of rubber sealing material, a new device of simulating downhole environment is designed to test the permeability of O-ring. The sample is hydrogenated nitrile O-ring and orth...

  18. Selective synthesis of secondary amines from nitriles using Pt nanowires as a catalyst.

    Science.gov (United States)

    Lu, Shuanglong; Wang, Jiaqing; Cao, Xueqin; Li, Xinming; Gu, Hongwei

    2014-04-04

    A new one-pot method has been developed for the selective synthesis of secondary amines via reductive amination of the corresponding nitriles using Pt nanowires as a catalyst. This method allows for the synthesis of both unsymmetrical and symmetrical secondary amines in excellent yields (up to 95%) in the presence or absence of additional amines, respectively. Furthermore, the reaction proceeds under mild conditions and is environmentally benign.

  19. Polymer Composites Based on Plasticized PVC and Vulcanized Nitrile Rubber Waste Powder for Irrigation Pipes

    OpenAIRE

    Maria Daniela Stelescu

    2013-01-01

    The paper presents the technique of production and characterization of polymer composites based on plasticized PVC and rubber powder from vulcanized nitrile rubber waste. The new polymer composites have lower hardness, higher elongation at break, a better tensile strength, and better ozone resistance, and the blend suitable for irrigations pipes for agricultural use was selected. The selected polymer composites have a good behavior under accelerated aging, repeated flexion at room temperature...

  20. High performance maleimide and nitrile functionalized benzoxazines with good processibility for advanced composite applications

    Science.gov (United States)

    Chaisuwan, Thanyalak

    A maleimide and 2-aminobenzonitrile (MIan) based benzoxazine has been synthesized and characterized. This benzoxazine has maleimide and nitrile functionalities that can polymerize, resulting in a highly crosslinked material. Incorporation of the imide group increases the shear viscosity compared to monofunctional benzoxazines but not as high as difunctional benzoxazines, allowing good processibility, while maintaining excellent mechanical and thermal properties. Catalysts, epoxy copolymerization, and rubber interlayer methods are utilized in order to optimize the composite properties. The 60% carbon cloth reinforced resin has achieved the flexural strength over 1 GPa. The model compound is synthesized to investigate the thermal polymerization of maleimide and 2-aminobenzonitrile-based (MIan) polybenzoxazine. The stable cyclic compound containing imine functionality is proposed to form during thermal polymerization, yielding polybenzoxazine with excellent thermal properties. The thermal properties of maleimide and 2-aminobenzonitrile (MIan) polybenzoxazine are improved significantly when the methylene diaminobenzonitrile compound, which produces the free radicals during the polymerization process, is incorporated into the system. These free radicals are stabilized due to the electron delocalization from nitrile functionalities and used to initiate the nitrile polymerization in the MIan benzoxazine.

  1. Nitrile versus isonitrile adsorption at interstellar grains surfaces. I. Hydroxylated surfaces

    Science.gov (United States)

    Bertin, M.; Doronin, M.; Fillion, J.-H.; Michaut, X.; Philippe, L.; Lattelais, M.; Markovits, A.; Pauzat, F.; Ellinger, Y.; Guillemin, J.-C.

    2017-02-01

    Context. Almost 20% of the 200 different species detected in the interstellar and circumstellar media present a carbon atom linked to nitrogen by a triple bond. Among these 37 molecules, 30 are nitrile R-CN compounds, the remaining seven belonging to the isonitrile R-NC family. How these species behave in presence of the grain surfaces is still an open question. Aims: In this contribution we investigate whether the difference between nitrile and isonitrile functional groups may induce differences in the adsorption energies of the related isomers at the surfaces of interstellar grains of different nature and morphologies. Methods: The question was addressed by means of a concerted experimental and theoretical study of the adsorption energies of CH3CN and CH3NC on the surface water ice and silica. The experimental determination of the molecule - surface interaction energies was carried out using temperature programmed desorption (TPD) under an ultra-high vacuum (UHV) between 70 and 160 K. Theoretically, the question was addressed using first principle periodic density functional theory (DFT) to represent the organized solid support. Results: The most stable isomer (CH3CN) interacts more efficiently with the solid support than the higher energy isomer (CH3NC) for water ice and silica. Comparing with the HCN and HNC pair of isomers, the simulations show an opposite behaviour, in which isonitrile HNC are more strongly adsorbed than nitrile HCN provided that hydrogen bonds are compatible with the nature of the model surface. Conclusions: The present study confirms that the strength of the molecule surface interaction between isomers is not related to their intrinsic stability but instead to their respective ability to generate different types of hydrogen bonds. Coupling TPD to first principle simulations is a powerful method for investigating the possible role of interstellar surfaces in the release of organic species from grains, depending on the environment.

  2. Biotransformation of β-keto nitriles to chiral (S)-β-amino acids using nitrilase and ω-transaminase.

    Science.gov (United States)

    Mathew, Sam; Nadarajan, Saravanan Prabhu; Sundaramoorthy, Uthayasuriya; Jeon, Hyunwoo; Chung, Taeowan; Yun, Hyungdon

    2017-04-01

    To enzymatically synthesize enantiomerically pure β-amino acids from β-keto nitriles using nitrilase and ω-transaminase. An enzyme cascade system was designed where in β-keto nitriles are initially hydrolyzed to β-keto acids using nitrilase from Bradyrhizobium japonicum and subsequently β-keto acids were converted to β-amino acids using ω-transaminases. Five different ω-transaminases were tested for this cascade reaction, To enhance the yields of β-amino acids, the concentrations of nitrilase and amino donor were optimized. Using this enzymatic reaction, enantiomerically pure (S)-β-amino acids (ee > 99%) were generated. As nitrilase is the bottleneck in this reaction, molecular docking analysis was carried out to depict the poor affinity of nitrilase towards β-keto acids. A novel enzymatic route to generate enantiomerically pure aromatic (S)-β-amino acids from β-keto nitriles is demonstrated for the first time.

  3. Dynamic and structural correlations in nanocomposites of silica with modified surface and carboxylated nitrile rubber.

    Science.gov (United States)

    Sala, Renata L; Oliveira Xavier, Tatielih P; Venâncio, Tiago; Arantes, Tatiane Moraes; Paranhos, Caio M; Camargo, Emerson R

    2016-03-15

    Distinct affinities between the organic and inorganic phases were observed in nanocomposites prepared through a colloidal route with carboxylated nitrile rubber and modified silica nanoparticles, which resulted in variable mechanical properties and improved thermal stability. Nanoparticles with modified surface affected the macromolecular arrangements of the elastomeric matrix, changing the final mechanical behavior of the nanocomposite, which could be predicted by the spin-lattice relaxation time measured by solid-state NMR. It was also possible to identify how each different nanoparticle affected the molecular dynamic of nanocomposite, correlating the dynamic-mechanical analysis with the NMR data of the saturated carbons of the elastomer. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Carbohydrates as efficient catalysts for the hydration of α-amino nitriles.

    Science.gov (United States)

    Chitale, Sampada; Derasp, Joshua S; Hussain, Bashir; Tanveer, Kashif; Beauchemin, André M

    2016-11-01

    Directed hydration of α-amino nitriles was achieved under mild conditions using simple carbohydrates as catalysts exploiting temporary intramolecularity. A broadly applicable procedure using both formaldehyde and NaOH as catalysts efficiently hydrated a variety of primary and secondary susbtrates, and allowed the hydration of enantiopure substrates to proceed without racemization. This work also provides a rare comparison of the catalytic activity of carbohydrates, and shows that the simple aldehydes at the basis of chemical evolution are efficient organocatalysts mimicking the function of hydratase enzymes. Optimal catalytic efficiency was observed with destabilized aldehydes, and with difficult substrates only simple carbohydrates such as formaldehyde and glycolaldehyde proved reliable.

  5. Isoxazolodihydropyridinones: 1,3-dipolar cycloaddition of nitrile oxides onto 2,4-dioxopiperidines

    Science.gov (United States)

    Coffman, Keith C.; Hartley, Timothy P.; Dallas, Jerry L.; Kurth, Mark J.

    2012-01-01

    Practical and efficient methods have been developed for the diversity-oriented synthesis of isoxazolodihydropyridinones via the 1,3-dipolar cycloaddition of nitrile oxides onto 2,4-dioxopiperidines. A select few of these isoxazolodihydropyridinones were further elaborated with triazoles by copper catalyzed azide-alkyne cycloaddition reactions. A total of 70 compounds and intermediates were synthesized and analyzed for drug likeness. Sixty-four of these novel compounds were submitted to the NIH Molecular Libraries Small Molecule Repository for high-throughput biological screening. PMID:22352295

  6. Palladium-Catalyzed, ortho-Selective C-H Halogenation of Benzyl Nitriles, Aryl Weinreb Amides, and Anilides.

    Science.gov (United States)

    Das, Riki; Kapur, Manmohan

    2017-01-20

    A palladium-catalyzed, ortho-selective C-H halogenation methodology is reported herein. The highlight of the work is the highly selective C(sp(2))-H functionalization of benzyl nitriles in the presence of activated C(sp(3))-H bond, which results in good yields of the halogenated products with excellent regioselectivity. Along with benzyl nitriles, aryl Weinreb amides and anilides have been evaluated for the transformation using aprotic conditions. Mechanistic studies yield interesting aspects with respect to the pathway of the reaction and the directing group abilities.

  7. A comparative DFT study of substrates and products of industrial enzyme nitrile hydratase

    Science.gov (United States)

    Peplowski, Lukasz; Kubiak, Karina; Zelek, Slawomir; Nowak, Wieslaw

    Nitrile hydratase (NHase) is a metalloenzyme used in industrial biotechnology for a large scale production of common chemicals. NHases convert nitriles to the corresponding amides. Although the structures of some forms of NHases containing nonheme low spin Fe(III) or low spin noncorrinoid Co(III) are known, neither a catalytic mechanism nor the reasons of high selectivity towards aromatic ligands are recognized. Optimized geometries, molecular electrostatic potential maps and infrared spectra of commercially important aromatic substrates of the NHase (nicotinonitrile, o-, m-, p-methylbenzonitrile) and the corresponding products (nicotinamide, o-, m-, p-methylbenzamid) were investigated using the density functional theory method with the B3LYP functional and the 6-31G(d,p) basis set. Calculated hypothetical intrinsic reaction paths indicate that benzimidic acids may be involved as intermediates. This study elucidates differences in the electronic properties of substrates and products of NHases, provides an insight into the molecular basis of the catalytic reaction and helps to explain varying enzymatic activities of microbial NHases.0

  8. Palladium(II) containing γ-Keggin silicodecatungstate that efficiently catalyzes hydration of nitriles.

    Science.gov (United States)

    Hirano, Tomohisa; Uehara, Kazuhiro; Kamata, Keigo; Mizuno, Noritaka

    2012-04-11

    A mixture of Pd(OAc)(2) and TBA(4)[γ-SiW(10)O(34)(H(2)O)(2)] (TBA-SiW10, TBA = [(n-C(4)H(9))(4)N](+)) showed high catalytic activities for hydration of various kinds of structurally diverse nitriles including aromatic, aliphatic, heteroaromatic, and double bond-containing ones. For hydration of 3-cyanopyridine, the turnover frequency was 860 h(-1), and the turnover number reached up to 670. A dipalladium-substituted γ-Keggin silicodecatungstate, [γ-H(2)SiW(10)O(36)Pd(2)(OAc)(2)](4-) (I), was successfully synthesized by the reaction of [γ-SiW(10)O(34)(H(2)O)(2)](4-) with Pd(OAc)(2) in a mixed solvent of acetone and water. The crystal structure of I was a monomeric, dipalladium-substituted, γ-Keggin silicodecatungstate with bidentate acetate ligands. Compound I showed similar activities and selectivities to those of a simple mixture of Pd(OAc)(2) and TBA-SiW10. The kinetic, mechanistic, and density functional theory calculation studies show that the dipalladium site plays an important role in the present hydration, and the nucleophilic attack of a hydroxide or water to the nitrile carbon atom is included in the rate-determining step. © 2012 American Chemical Society

  9. Retrievals of abundances of hydrocarbon and nitrile species in Titan’s upper atmosphere

    Science.gov (United States)

    Yung, Yuk; Fan, Siteng; Shemansky, D. E.; Li, Cheng; Gao, Peter

    2017-10-01

    We develop an innovative retrieval method for Titan occultation measurements by the Cassini UVIS experiment. The T35 occultation is analyzed to illustrate the methodology. A significant number of occultations observed using the UVIS spectrographs show loss of pointing control required for correction of the spectral vectors. Consequently, only three stellar occultations have been analyzed to date. We use the Markov Chain Monte-Carlo (MCMC) method to retrieve the abundances or upper limits of thirteen hydrocarbon and nitrile species (N2, CH4, C2H2, C2H4, C2H6, HCN, C4H2, C6N2, C6H6, tholin, HC3N, C2N2, NH3) along with the pointing error using the Cassini/UVIS simulator. These numbers are derived for the fast T35 occultation, which has never been analyzed because of large pointing errors. Uncertainty in the retrievals is determined using an intrinsic fitting probability distribution function. The Caltech/JPL photochemical and kinetics model, KINETICS, is used to calculate the atmospheric aforementioned species. Comparisons between model and observations reveal gaps in our current understanding of the chemical kinetics of hydrocarbons and nitrile species, especially for C6H6.

  10. Permeability test and fuzzy orthogonal analysis of hydrogenated nitrile O-ring

    Directory of Open Access Journals (Sweden)

    Qin Hu

    2015-03-01

    Full Text Available In the high temperature, high pressure and high corrosive environment of the oil and gas drilling downhole, the weatherability of rubber sealing material has a great influence on the production safety. In order to study the important degree of every key environmental factor in downhole influencing the sealing performance of rubber sealing material, a new device of simulating downhole environment is designed to test the permeability of O-ring. The sample is hydrogenated nitrile O-ring and orthogonal experiment method is used to do nine tests by getting three levels from temperature, pressure and CO2 volume fraction. Test adopts fuzzy orthogonal method to analyze the main effects and the interaction between two factors, taking tensile strength, diameter variety rate and pH value of indicator as evaluation index. The results show that: the environmental factor influencing the sealing performance of hydrogenated nitrile O-ring from high to low by turns is temperature, pressure and CO2 volume fraction, while the interaction between temperature and pressure is the most significant. It provides a new way to study the influence of downhole complex environment on the performance of rubber sealing material. Moreover, the results have important reference value to further study the failure mechanism of rubber sealing ring in many environmental factors and the rational use in engineering.

  11. D-π-A Compounds with Tunable Intramolecular Charge Transfer Achieved by Incorporation of Butenolide Nitriles as Acceptor Moieties

    DEFF Research Database (Denmark)

    Moreno-Yruela, Carlos; Garín, Javier; Orduna, Jesús

    2015-01-01

    Chromophores where a polyenic spacer separates a 4H-pyranylidene or benzothiazolylidene donor and three different butenolide nitriles have been synthesized and characterized. The role of 2(5H)-furanones as acceptor units on the polarization and the second-order nonlinear (NLO) properties has been...

  12. A facile one-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica: Aqueous hydration of nitriles to amides

    Science.gov (United States)

    One-pot synthesis of ruthenium hydroxide nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium hydroxide immobilization; the hydration of nitriles occurs in high yield and excellent selectivity using this...

  13. Synthesis of enantiopure imidazolines through a Ritter reaction of 2-(1-aminoalkyl)aziridines with nitriles.

    Science.gov (United States)

    Concellón, José M; Riego, Estela; Suárez, José Ramón; García-Granda, Santiago; Díaz, M Rosario

    2004-11-25

    The Ritter reaction of enantiopure 2-(1-aminoalkyl)aziridines 1 with different nitriles afford enantiopure tetrasubstituted imidazolines 2. The opening of the aziridine ring takes place with total regio- and stereoselectivity. A mechanism to explain the described addition reaction is proposed. [reaction: see text

  14. Expansion of ribosomally produced natural products: a nitrile hydratase- and Nif11-related precursor family

    Directory of Open Access Journals (Sweden)

    Mitchell Douglas A

    2010-05-01

    Full Text Available Abstract Background A new family of natural products has been described in which cysteine, serine and threonine from ribosomally-produced peptides are converted to thiazoles, oxazoles and methyloxazoles, respectively. These metabolites and their biosynthetic gene clusters are now referred to as thiazole/oxazole-modified microcins (TOMM. As exemplified by microcin B17 and streptolysin S, TOMM precursors contain an N-terminal leader sequence and C-terminal core peptide. The leader sequence contains binding sites for the posttranslational modifying enzymes which subsequently act upon the core peptide. TOMM peptides are small and highly variable, frequently missed by gene-finders and occasionally situated far from the thiazole/oxazole forming genes. Thus, locating a substrate for a particular TOMM pathway can be a challenging endeavor. Results Examination of candidate TOMM precursors has revealed a subclass with an uncharacteristically long leader sequence closely related to the enzyme nitrile hydratase. Members of this nitrile hydratase leader peptide (NHLP family lack the metal-binding residues required for catalysis. Instead, NHLP sequences display the classic Gly-Gly cleavage motif and have C-terminal regions rich in heterocyclizable residues. The NHLP family exhibits a correlated species distribution and local clustering with an ABC transport system. This study also provides evidence that a separate family, annotated as Nif11 nitrogen-fixing proteins, can serve as natural product precursors (N11P, but not always of the TOMM variety. Indeed, a number of cyanobacterial genomes show extensive N11P paralogous expansion, such as Nostoc, Prochlorococcus and Cyanothece, which replace the TOMM cluster with lanthionine biosynthetic machinery. Conclusions This study has united numerous TOMM gene clusters with their cognate substrates. These results suggest that two large protein families, the nitrile hydratases and Nif11, have been retailored for

  15. Magnesium(I) dimers as reagents for the reductive coupling of isonitriles and nitriles.

    Science.gov (United States)

    Ma, Mengtao; Stasch, Andreas; Jones, Cameron

    2012-08-20

    The reactivity of two β-diketiminate coordinated magnesium(I) dimers, [LMgMgL], L=[(RNCMe)(2) CH](-) , R=C(6) H(3) iPr(2) -2,6 ((Dip) Nacnac(-) ) or mesityl ((Mes) Nacnac(-) ), towards a series of isonitriles and nitriles have been examined. Reactions with the isonitriles, RN≡C: (R=tBu or C(6) H(3) Me(2) -2,6 (Xyl)), led to reductive C-C couplings and the formation of [{((Dip) Nacnac)Mg}(2) {μ-(XylN=C-)(2) }] and [{((Mes) Nacnac)Mg}(2) {μ-(tBuN=C-)(2) }], or a reductive N-C cleavage and the generation of the magnesium cyanide complex, [{((Dip) Nacnac)Mg(μ-CN)}(3) ]. Reactions of the magnesium dimers with benzonitrile, PhC≡N, afforded the C-C-coupled products, [((Dip) Nacnac)Mg[μ-{N=C(Ph)-}(2) ]Mg(NCPh)((Dip) Nacnac)], and [{{((Mes) Nacnac)Mg}(2) [μ-{N=C(Ph)-}(2) ]}(2) ], whereas the reductive CC cleavage of tBuC≡N gave rise to a mixture of [((Dip) Nacnac)Mg(tBu)(NCtBu)] and [{((Dip) Nacnac)Mg(μ-CN)}(3) ]. In contrast, a combination of net nitrile isomerization and C-C coupling processes was involved in the reduction of Me(3) SiC≡N, which yielded [{((Dip) Nacnac)Mg}(2) {μ-(Me(3) SiN=C-)(2) }]. All new compounds were crystallographically and spectroscopically characterized. The outcomes of the reported reactions were found to be dependent upon both the steric bulk of the magnesium(I) reagent, and the nature of the isonitrile/nitrile substituent. This combined with a high degree of selectivity for the reactions, indicates that magnesium(I) dimers may find use by organic and organometallic chemists as viable alternatives to currently available reducing agents that are utilized for the reduction of unsaturated organic substrates. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Experimental studies and performance analyses on polyurethane and nitrile rubber rod seals

    Science.gov (United States)

    Mirza, M.; Temiz, V.; Kamburoǧlu, E.

    2012-09-01

    The aim of this study is to determine the friction and leakage properties of rod seals made of polyethylene and nitrile rubber with different design geometries, under various pressure and lubricating oil viscosity conditions, in order to make assumptions about their general sealing characteristics and their pros and cons under certain working conditions that involve a range of fluid pressures. The test specimens consist of commercial rod seals of various designs and materials and were mounted on a hard chrome coated shaft subject to reciprocating motion. The test rig is capable of measuring friction force by means of strain measurements on a load cell transmitting the linear motion of a screw shaft to the test shaft. The test results of the reciprocating rod seal samples were evaluated according to leakage amount and friction resistance as a function of materials, design geometries and fluid pressures as well as the lubricating oil viscosity.

  17. Application of protective coatings from ultrahigh-molecular weight polyethylene to butadiene-nitrile rubber

    Science.gov (United States)

    Dyakonov, A. A.; Sokolova, M. D.; Shadrinov, N. V.; Sleptsova, S. A.

    2017-12-01

    The paper presents a method of applying a protective coating from ultrahigh molecular weight polyethylene to rubber products. A distinctive feature of the presented method is the prevulcanization of a rubber compound in order to form it into the desired shape and remove an excess rubber material. The application of an ultrahigh molecular weight polyethylene powder to the prepared surface ensures a uniform coating thickness. To achieve an optimal combination of rubber properties, we study how the scorch time affects its physical and mechanical properties, hardness, corrosion, abrasion and thermal resistance. We find the scorch time range in which a spatial elastomeric network forms that influences the penetration of ultrahigh molecular weight polyethylene into butadiene-nitrile rubber.

  18. Investigation on thermal oxidative aging of nitrile rubber (NBR) O-rings under compression stress

    Science.gov (United States)

    Liu, X. R.; Zhang, W. F.; Lou, W. T.; Huang, Y. X.; Dai, W.

    2017-11-01

    The degradation behaviors of nitrile rubber O-rings exposure to air under compression were investigated at three elevated temperatures. The physical and mechanical properties of the aging samples before and after exposure at selected time were studied by measuring weight loss, tensile strength and elongation at break. The Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and fracture morphology were used to reveal the microstructural changes of the aging samples. The results indicate that the weight decreased with exposure time and temperature. Based on the results of the crosslinking density, the crosslinking predominates during the most of aging process. The significant changes in tensile strength and elongation at break also indicate the severe degradation in air. The fracture morphology results show that the fracture surface after 64 days of exposure to air turns rough and present defects. The ATR-FTIR results demonstrate that the hydroxyl groups were formed for the samples aged in air.

  19. Low percolation threshold carbon-black/ nitrile-butadiene-rubber composites and their electromagnetic shielding effects.

    Science.gov (United States)

    Zeng, Min; Zhao, Dongliang; Yu, Ronghai; Feng, Meng; Yang, Bai; Liu, Xiaofang; Zhang, Yanghuan; Wang, Xinlin

    2013-02-01

    Nitrile-butadiene-rubber composites, filled with super conducting carbon black, are successfully prepared with low percolation threshold, high conductivity and electromagnetic shielding effectiveness. Percolation theory is used to represent the system's conductivity, and the corresponding result is close to the experimental value. The fitting curve also gives the weight fraction threshold and conductivity exponent of the conducting polymer. The percolation threshold of the composite is 9.2 phr, which is much smaller than previous homologous findings and lower than the value of short carbon fiber counterparts reported. The volume resistivity becomes 3.17 omega x cm for the 20 phr sample and decreases to 0.66 omega x cm for the 40 phr sample. At 1.8 GHz for 40 phr sample, the shielding effectiveness is -43 dB.

  20. Sensitivity of core-level spectroscopy to electrostatic environments of nitrile groups: An ab initio study

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    2017-09-01

    Full Text Available Ab initio quantum chemistry calculations have been performed to probe the influence of hydrogen bonding on the electronic structure of hydrogen cyanide (HCN. Our calculations determine the origin of nitrogen-specific Raman spectral features from resonant inelastic X-ray scattering occurring in the presence of a water molecule and an electric dipole field. The similarity of the two interactions in altering the electronic structure of the nitrogen atom differs only in the covalent contributions from the water molecule. The CN stretching mode as a structural probe was also investigated to study the electronic origin of the anomalous frequency shift of the nitrile group when subjected to hydrogen bonding and an electrostatic dipole field. The major changes in the electronic structure of HCN are electrostatic in nature and originate from dipole-dipole interactions. The relative shifts of the CN stretching frequency are in good agreement with those experimentally observed.

  1. Nitrile versus isonitrile adsorption at interstellar grain surfaces. II. Carbonaceous aromatic surfaces

    Science.gov (United States)

    Bertin, M.; Doronin, M.; Michaut, X.; Philippe, L.; Markovits, A.; Fillion, J.-H.; Pauzat, F.; Ellinger, Y.; Guillemin, J.-C.

    2017-12-01

    Context. Almost 20% of the 200 different species detected in the interstellar and circumstellar media present a carbon atom linked to nitrogen by a triple bond. Of these 37 molecules, 30 are nitrile R-CN compounds, the remaining 7 belonging to the isonitrile R-NC family. How these species behave in their interactions with the grain surfaces is still an open question. Aims: In a previous work, we have investigated whether the difference between nitrile and isonitrile functional groups may induce differences in the adsorption energies of the related isomers at the surfaces of interstellar grains of various nature and morphologies. This study is a follow up of this work, where we focus on the adsorption on carbonaceous aromatic surfaces. Methods: The question is addressed by means of a concerted experimental and theoretical approach of the adsorption energies of CH3CN and CH3NC on the surface of graphite (with and without surface defects). The experimental determination of the molecule and surface interaction energies is carried out using temperature-programmed desorption in an ultra-high vacuum between 70 and 160 K. Theoretically, the question is addressed using first-principle periodic density functional theory to represent the organised solid support. Results: The adsorption energy of each compound is found to be very sensitive to the structural defects of the aromatic carbonaceous surface: these defects, expected to be present in a large numbers and great diversity on a realistic surface, significantly increase the average adsorption energies to more than 50% as compared to adsorption on perfect graphene planes. The most stable isomer (CH3CN) interacts more efficiently with the carbonaceous solid support than the higher energy isomer (CH3NC), however.

  2. Crystallization and preliminary X-ray characterization of the nitrile reductase QueF: a queuosine-biosynthesis enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Swairjo, Manal A., E-mail: swairjo@scripps.edu; Reddy, Robert R. [Departments of Chemistry and Molecular Biology, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, BCC-379, La Jolla, CA 92037 (United States); Lee, Bobby; Van Lanen, Steven G. [Department of Chemistry, Portland State University, PO Box 751, Portland, OR 97207 (United States); Brown, Shannon [Departments of Chemistry and Molecular Biology, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, BCC-379, La Jolla, CA 92037 (United States); Crécy-Lagard, Valérie de [Department of Microbiology and Cell Science, University of Florida, PO Box 110700, Gainesville, FL 32611-0700 (United States); Iwata-Reuyl, Dirk [Department of Chemistry, Portland State University, PO Box 751, Portland, OR 97207 (United States); Schimmel, Paul [Departments of Chemistry and Molecular Biology, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, BCC-379, La Jolla, CA 92037 (United States)

    2005-10-01

    Structural informatics and modelling correctly predicted that substrate was required to obtain diffracting crystals of the first characterized nitrile oxidoreductase: the homododecameric QueF. QueF (MW = 19.4 kDa) is a recently characterized nitrile oxidoreductase which catalyzes the NADPH-dependent reduction of 7-cyano-7-deazaguanine (preQ{sub 0}) to 7-aminomethyl-7-deazaguanine, a late step in the biosynthesis of the modified tRNA nucleoside queuosine. Initial crystals of homododecameric Bacillus subtilis QueF diffracted poorly to 8.0 Å. A three-dimensional model based on homology with the tunnel-fold enzyme GTP cyclohydrolase I suggested catalysis at intersubunit interfaces and a potential role for substrate binding in quaternary structure stabilization. Guided by this insight, a second crystal form was grown that was strictly dependent on the presence of preQ{sub 0}. This crystal form diffracted to 2.25 Å resolution.

  3. Preparation and characterization of electrospun poly(phthalazinone ether nitrile ketone) membrane with novel thermally stable properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gang; Zhang, Hao; Qian, Bingqing [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Wang, Jinyan, E-mail: wangjinyan@dlut.edu.cn [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116024 (China); Jian, Xigao [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116024 (China); Qiu, Jieshan, E-mail: jqiu@dlut.edu.cn [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China)

    2015-10-01

    Highlights: • Poly (phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. • Electrospun membrane exhibits a good thermostability. • Electrospun membrane. - Abstract: Electrospun nanofibrous membranes have several applications because of their excellent properties, such as high porosity, small fiber diameter, and large surface area. However, high-temperature resistant electrospun membranes remain a challenge because of the absence of precursors that offer spinnability, scalability, and superior thermal stability. In this study, poly(phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. Electrospun PPENK membranes were characterized by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, and tensile stress–strain tests. Results indicated that the prepared electrospun membranes had a very high glass transition temperature, superior chemical resistance, and excellent mechanical strength. These desirable properties broaden their potential application in membranes and treatment of various hot fluid streams without strict temperature control.

  4. Thermomechanical properties of zirconium tungstate/hydrogenated nitrile butadiene rubber (HNBR) composites for low-temperature applications

    OpenAIRE

    Akulichev, Anton G.; Alcock, Ben; Tiwari, Avinash; Echtermeyer, Andreas T.

    2017-01-01

    Rubber compounds for pressure sealing application typically have inferior dimensional stability with temperature fluctuations compared with their steel counterparts. This effect may result in seal leakage failures when subjected to decreases in temperature. Composites of hydrogenated nitrile butadiene rubber (HNBR) and zirconium tungstate as a negative thermal expansion filler were prepared in order to control the thermal expansivity of the material. The amount of zirconium tungstate (ZrW2O8)...

  5. Permeation of Limonene through Disposable Nitrile Gloves in the Robot Hand Whole Glove and ASTM Closed Loop Models

    OpenAIRE

    Banaee, Sean

    2015-01-01

    The ultimate purpose was to assess if a whole glove dextrous robotic hand model provided results that differed from the reference modified closed-loop ASTM F739-99/12 glove permeation technique. The candidate compounds were low volatile solvents to minimize the influence of volatilization as a confounding factor. After preliminary closed-loop studies with 2-ethoxyethanol and 2-butoxyethanol showed the breakthrough times for purple nitrile disposable gloves were too short to be compared in th...

  6. Biosynthesis of the Nitrile Glucosides Rhodiocyanoside A and D and the Cyanogenic Glucosides Lotaustralin and Linamarin in Lotus japonicus1

    Science.gov (United States)

    Forslund, Karin; Morant, Marc; Jørgensen, Bodil; Olsen, Carl Erik; Asamizu, Erika; Sato, Shusei; Tabata, Satoshi; Bak, Søren

    2004-01-01

    Lotus japonicus was shown to contain the two nitrile glucosides rhodiocyanoside A and rhodiocyanoside D as well as the cyanogenic glucosides linamarin and lotaustralin. The content of cyanogenic and nitrile glucosides in L. japonicus depends on plant developmental stage and tissue. The cyanide potential is highest in young seedlings and in apical leaves of mature plants. Roots and seeds are acyanogenic. Biosynthetic studies using radioisotopes demonstrated that lotaustralin, rhodiocyanoside A, and rhodiocyanoside D are derived from the amino acid l-Ile, whereas linamarin is derived from Val. In silico homology searches identified two cytochromes P450 designated CYP79D3 and CYP79D4 in L. japonicus. The two cytochromes P450 are 94% identical at the amino acid level and both catalyze the conversion of Val and Ile to the corresponding aldoximes in biosynthesis of cyanogenic glucosides and nitrile glucosides in L. japonicus. CYP79D3 and CYP79D4 are differentially expressed. CYP79D3 is exclusively expressed in aerial parts and CYP79D4 in roots. Recombinantly expressed CYP79D3 and CYP79D4 in yeast cells showed higher catalytic efficiency with l-Ile as substrate than with l-Val, in agreement with lotaustralin and rhodiocyanoside A and D being the major cyanogenic and nitrile glucosides in L. japonicus. Ectopic expression of CYP79D2 from cassava (Manihot esculenta Crantz.) in L. japonicus resulted in a 5- to 20-fold increase of linamarin content, whereas the relative amounts of lotaustralin and rhodiocyanoside A/D were unaltered. PMID:15122013

  7. Biosynthesis of the nitrile glucosides rhodiocyanoside A and D and the cyanogenic glucosides lotaustralin and linamarin in Lotus japonicus.

    Science.gov (United States)

    Forslund, Karin; Morant, Marc; Jørgensen, Bodil; Olsen, Carl Erik; Asamizu, Erika; Sato, Shusei; Tabata, Satoshi; Bak, Søren

    2004-05-01

    Lotus japonicus was shown to contain the two nitrile glucosides rhodiocyanoside A and rhodiocyanoside D as well as the cyanogenic glucosides linamarin and lotaustralin. The content of cyanogenic and nitrile glucosides in L. japonicus depends on plant developmental stage and tissue. The cyanide potential is highest in young seedlings and in apical leaves of mature plants. Roots and seeds are acyanogenic. Biosynthetic studies using radioisotopes demonstrated that lotaustralin, rhodiocyanoside A, and rhodiocyanoside D are derived from the amino acid l-Ile, whereas linamarin is derived from Val. In silico homology searches identified two cytochromes P450 designated CYP79D3 and CYP79D4 in L. japonicus. The two cytochromes P450 are 94% identical at the amino acid level and both catalyze the conversion of Val and Ile to the corresponding aldoximes in biosynthesis of cyanogenic glucosides and nitrile glucosides in L. japonicus. CYP79D3 and CYP79D4 are differentially expressed. CYP79D3 is exclusively expressed in aerial parts and CYP79D4 in roots. Recombinantly expressed CYP79D3 and CYP79D4 in yeast cells showed higher catalytic efficiency with l-Ile as substrate than with l-Val, in agreement with lotaustralin and rhodiocyanoside A and D being the major cyanogenic and nitrile glucosides in L. japonicus. Ectopic expression of CYP79D2 from cassava (Manihot esculenta Crantz.) in L. japonicus resulted in a 5- to 20-fold increase of linamarin content, whereas the relative amounts of lotaustralin and rhodiocyanoside A/D were unaltered.

  8. Nitrile-functionalized ruthenium nanoparticles: charge delocalization through Ru − N ≡ C interface

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fengqi; Huang, Lin; Zou, Jiasui [South China University of Technology, New Energy Research Institute, School of Environment and Energy, Guangzhou Higher Education Mega Centre (China); Yan, Jinwu; Zhu, Jiaying [South China University of Technology, School of Bioscience and Bioengineering, Guangzhou Higher Education Mega Centre (China); Kang, Xiongwu, E-mail: esxkang@scut.edu.cn; Chen, Shaowei, E-mail: shaowei@ucsc.edu [South China University of Technology, New Energy Research Institute, School of Environment and Energy, Guangzhou Higher Education Mega Centre (China)

    2017-03-15

    Ruthenium nanoparticles (2.06 ± 0.46 nm in diameter) were stabilized by the self-assembly of nitrile molecules onto the ruthenium colloid surface by virtue of the formation of Ru−N≡C interfacial bonding linkages. Thermogravimetric analysis showed that there were about 63 nitrile ligands per nanoparticle, corresponding to an average molecular footprint of 22.4 Å{sup 2}. Proton nuclear magnetic resonance (NMR) studies suggested an end-on configuration of the nitrile moiety on the metal core surface. Meanwhile, infrared measurements showed that the C≡N stretch red-shifted from 2246 to 1944 cm{sup −1} upon adsorption on the nanoparticle surfaces, as confirmed by {sup 15}N isotopic labeling. This apparent red-shift suggests extensive intraparticle charge delocalization, which was further manifested by photoluminescence measurements of 1-cyanopyrene-functionalized ruthenium nanoparticles that exhibited a red shift of 40 nm of the emission maximum, in comparison to that of free monomers. The results further highlight the significance of metal−organic contacts in the manipulation of the dynamics of intraparticle charge transfer and the nanoparticle optical and electronic properties.

  9. Selective N-alkylation of amines using nitriles under hydrogenation conditions: facile synthesis of secondary and tertiary amines.

    Science.gov (United States)

    Ikawa, Takashi; Fujita, Yuki; Mizusaki, Tomoteru; Betsuin, Sae; Takamatsu, Haruki; Maegawa, Tomohiro; Monguchi, Yasunari; Sajiki, Hironao

    2012-01-14

    Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH(4)OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.

  10. Production and Characterization of a Nitrilase from Pseudomonas aeruginosa RZ44 and its Potential for Nitrile Biotransformation.

    Science.gov (United States)

    Badoei-Dalfard, Arastoo; Ramezani-Pour, Narjes; Karami, Zahra

    2016-09-01

    The conversion of nitriles into amides or carboxylic acids by nitrilase has taken its application into consideration, as the scope of its applications has recently been extended. In this study, P. aeruginosa RZ44 was isolated from sewage in the Kerman which has Nitrile-degradation activity. In order to improve the nitrilase production, several optimization were done on environmental condition. Nitrilase activity was characterized against different pHs, temperatures, ions, and substrates. Enzyme activity was evaluated by determining the production of ammonia following to the modification of the phenol/hypochlorite method. Different factors that affect production of the enzyme by P. aeruginosa RZ44 were optimized and evaluated in the culture mediums. The results showed that degradation of the acetonitrile by P. aeruginosa RZ44 increased the pH of the growth medium from the initial pH 7.0 to 9.37. Optimizing the medium for P. aeruginosa RZ44, it was found that glucose and starch (5 g.L(-1)) have strongly supported nitrilase production, compared to the control. As well, urea (5 g.L(-1)) and yeast extract (15 g.L(-1)) have favored an increased biomass and nitrilase production, as the nitrogen sources. These results show that nitrilase production increases in the pH range 5.0 to 7.0 and then start decreasing. Addition of the Mg(2+), Fe(2+) and Na(+) has supported the biomass and nitrilase production. Co(2+), Mn(2+) and Cu(2+) were confirmed to inhibit cell growth and enzyme production. Enzyme characterization results show that, P. aeruginosa RZ44 nitrilase exhibits comparatively high activity and stability at pH 7.0 and 40°C. Nitrilase was completely inhibited by CoCl2 and CaCl2, whereas, the inhibition in the presence of MnSO4 and CuSO4 was about 60%. Time course analysis of the nitrile conversion by the resting P. aeruginosa RZ44 cells showed that nitrile substrates (i.e. acetonitrile) was hydrolyzed within 8 h. these results indicate that P. aeruginosa RZ44 has the

  11. Activity Enhancement Based on the Chemical Equilibrium of Multiple-Subunit Nitrile Hydratase from Bordetella petrii.

    Science.gov (United States)

    Liu, Yi; Liu, Ping; Lin, Lu; Zhao, Yueqin; Zhong, Wenjuan; Wu, Lunjie; Zhou, Zhemin; Sun, Weifeng

    2016-09-01

    The maturation mechanism of nitrile hydratase (NHase) of Pseudomonas putida NRRL-18668 was discovered and named as "self-subunit swapping." Since the NHase of Bordetella petrii DSM 12804 is similar to that of P. putida, the NHase maturation of B. petrii is proposed to be the same as that of P. putida. However, there is no further information on the application of NHase according to these findings. We successfully rapidly purified NHase and its activator through affinity his tag, and found that the cell extracts of NHase possessed multiple types of protein ingredients including α, β, α2β2, and α(P14K)2 who were in a state of chemical equilibrium. Furthermore, the activity was significantly enhanced through adding extra α(P14K)2 to the cell extracts of NHase according to the chemical equilibrium. Our findings are useful for the activity enhancement of multiple-subunit enzyme and for the first time significantly increased the NHase activity according to the chemical equilibrium.

  12. Identification of Semicarbazones, Thiosemicarbazones and Triazine Nitriles as Inhibitors of Leishmania mexicana Cysteine Protease CPB

    Science.gov (United States)

    Schröder, Jörg; Noack, Sandra; Marhöfer, Richard J.; Mottram, Jeremy C.; Coombs, Graham H.; Selzer, Paul M.

    2013-01-01

    Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas’ disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases. PMID:24146999

  13. Identification of semicarbazones, thiosemicarbazones and triazine nitriles as inhibitors of Leishmania mexicana cysteine protease CPB.

    Directory of Open Access Journals (Sweden)

    Jörg Schröder

    Full Text Available Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas' disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases.

  14. Synthesis, characterization and rheological property of biphenyl-based polyarylene ether nitrile copolymers

    Directory of Open Access Journals (Sweden)

    2007-08-01

    Full Text Available The high molecular weight biphenyl-based polyarylene ether nitrile copolymers were synthesized by nucleophilic substitution reaction of 2,6-dichlorobenzonitrile (DCBN with varying molar ratios of 4,4’-dihydroxybiphenyl (BP and hydroquinone (HQ. The BP content of the copolymers has influence on glass transition temperature (Tg, initial decomposition temperature (Tid, mechanical properties and the crystallinity. All the copolymers could be dissolved in NMP, DMF and DMAc on heating, and were stable up to 450°C with a high char yield above 50% at 800°C in nitrogen atmosphere. The glass transition temperature, the melting temperature and tensile strength of copolymers were found to increase with increase in concentration of the BP units in the polymer. The dynamical viscosity and the storage modulus have been influenced by the BP concentration, frequency, temperature and time. This rheological results show that these copolymers have best thermoplastic processability and stability at 300–400°C.

  15. Swelling and tribological properties of melt-mixed fluoroelastomer/nitrile rubber blends under crude oil

    Science.gov (United States)

    Tagelsir, Yasin; Li, San-Xi; Lv, Xiaoren; Wang, Shijie; Wang, Song; Osman, Zeinab

    2018-01-01

    The melt-mixed fluoroelastomer (FKM)/ nitrile rubber (NBR) blends of (90/10, 80/20, 70/30, 60/40 and 50/50) ratios with same hardness were prepared, and their swelling and tribological properties under crude oil were investigated for the purpose of developing high performance cost-effective elastomers meeting requirement of oil extraction progressive cavity pump stator. Differential scanning calorimetry confirmed compatible blend system for all blends. Field emission scanning electron microscopy (FE-SEM) showed co-continuous morphology of 200–400 nm phase size for all blends, expect FKM/NBR (90/10) which exhibited partially continuous phase morphology of 100–250 nm phase size. The results of swelling and linear wear tests under crude oil indicated that swelling percentage, coefficient of friction and specific wear rate of FKM/NBR blends were much better than NBR, with FKM/NBR (90/10 and 80/20) showing swelling percentage and specific wear rate very close to FKM. Attenuated total reflectance-Fourier transform infrared spectroscopy disclosed that fracture of macromolecular chains was the main mechanochemical effect of unswollen and swollen worn surfaces, in addition to oxygenated degradation detected with increasing NBR ratio in the blends. The fracture of macromolecular chains resulted in slight fatigue wear mechanism, which was also confirmed by FE-SEM of the worn surfaces.

  16. Sound Absorption Properties Of Single-Hole Hollow Polyester Fiber Reinforced Hydrogenated Carboxyl Nitrile Rubber Composites

    Directory of Open Access Journals (Sweden)

    Jie Hong

    2017-09-01

    Full Text Available A series of single-hole hollow polyester fiber (SHHPF reinforced hydrogenated carboxyl nitrile rubber (HXNBR composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM, and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

  17. Permeation of limonene through disposable nitrile gloves using a dextrous robot hand.

    Science.gov (United States)

    Banaee, Sean; S Que Hee, Shane

    2017-03-28

    The purpose of this study was to investigate the permeation of the low-volatile solvent limonene through different disposable, unlined, unsupported, nitrile exam whole gloves (blue, purple, sterling, and lavender, from Kimberly-Clark). This study utilized a moving and static dextrous robot hand as part of a novel dynamic permeation system that allowed sampling at specific times. Quantitation of limonene in samples was based on capillary gas chromatography-mass spectrometry and the internal standard method (4-bromophenol). The average post-permeation thicknesses (before reconditioning) for all gloves for both the moving and static hand were more than 10% of the pre-permeation ones (P≤0.05), although this was not so on reconditioning. The standardized breakthrough times and steady-state permeation periods were similar for the blue, purple, and sterling gloves. Both methods had similar sensitivity. The lavender glove showed a higher permeation rate (0.490±0.031 μg/cm2/min) for the moving robotic hand compared to the non-moving hand (P≤0.05), this being ascribed to a thickness threshold. Permeation parameters for the static and dynamic robot hand models indicate that both methods have similar sensitivity in detecting the analyte during permeation and the blue, purple, and sterling gloves behave similarly during the permeation process whether moving or non-moving.

  18. Natural rubber/nitrile butadiene rubber/hindered phenol composites with high-damping properties

    Directory of Open Access Journals (Sweden)

    Xiuying Zhao

    2015-10-01

    Full Text Available New natural rubber (NR/nitrile butadiene rubber (NBR/hindered phenol (AO-80 composites with high-damping properties were prepared in this study. The morphological, structural, and mechanical properties were characterized by atomic force microscopy (AFM, polarized Fourier transform infrared spectrometer (FTIR, dynamic mechanical thermal analyzer (DMTA, and a tensile tester. Each composite consisted of two phases: the NR phase and the NBR/AO-80 phase. There was partial compatibility between the NR phase and the NBR/AO-80 phase, and the NR/NBR/AO-80 (50/50/20 composite exhibited a co-continuous morphology. Strain-induced crystallization occurred in the NR phase at strains higher than 200%, and strain-induced orientation appeared in the NBR/AO-80 phase with the increase of strain from 100% to 500%. The composites had a special stress–strain behavior and mechanical properties because of the simultaneous strain-induced orientation and strain-induced crystallization. In the working temperature range of a seismic isolation bearing, the composites (especially the NR/NBR/AO-80 (50/50/20 composite presented a high loss factor, high area of loss peak (TA, and high hysteresis energy. Therefore, the NR/NBR/AO-80 rubber composites are expected to have important application as a high-performance damping material for rubber bearing.

  19. Ionic elastomers based on carboxylated nitrile rubber (XNBR and magnesium aluminum layered double hydroxide (hydrotalcite

    Directory of Open Access Journals (Sweden)

    A. Laskowska

    2014-06-01

    Full Text Available The presence of carboxyl groups in carboxylated nitrile butadiene rubber (XNBR allows it to be cured with different agents. This study considers the effect of crosslinking of XNBR by magnesium aluminum layered double hydroxide (MgAl-LDH, known also as hydrotalcite (HT, on rheometric, mechano-dynamical and barrier properties. Results of XNBR/HT composites containing various HT loadings without conventional curatives are compared with XNBR compound crosslinked with commonly used zinc oxide. Hydrotalcite acts as an effective crosslinking agent for XNBR, as is particularly evident from rheometric and Fourier transform infrared spectroscopy (FTIR studies. The existence of ionic crosslinks was also detected by dynamic mechanical analysis (DMA of the resulting composites. DMA studies revealed that the XNBR/HT composites exhibited two transitions – one occurring at low temperature is associated to the Tg of elastomer and the second at high temperature corresponds to the ionic transition temperature Ti. Simultaneous application of HT as a curing agent and a filler may deliver not only environmentally friendly, zinc oxide-free rubber product but also ionic elastomer composite with excellent mechanical, barrier and transparent properties.

  20. Effect of Nanoclay on Mechanical Properties and Ablation Behavior of a Nitrile-Based Heat Insulator

    Directory of Open Access Journals (Sweden)

    Fatemeh Arabgol

    2013-02-01

    Full Text Available Thermal insulation of rocket motor chamber is one of the most important functions of elastomeric ablative material. Combustion of solid rocket motor propellant produces turbulent media containing gases with a velocity more than 1000 m/s, temperature and pressure more than 3000°C and 10 MPa, respectively,which destroys all metallic alloys. Elastomeric nanocomposite heat insulators are more attractive subjects in comparison to their non-elastomeric counterparts, due to their excellent thermal stresses and larger deformation bearing capacity. Nitrile rubber with high thermal properties is a proper candidate in such applications. Development in ablation performance of these heat shields is considered as an important challenge nowadays. A few works have been recently carried out using organoclay to enhancethe ablation and mechanical properties of heat insulators. In this work, an elastomeric heat insulator with superior ablative and mechanical properties was presented using nanotechnology. The results showed that an elastomeric nanocomposite heat insulator containing 15 wt% organoclay exhibits superior characteristics compared to its composite counterpart such as: 46% more tensile strength, 60% more elongationat-break, 1.7 times higher modulus (at 100% strain, 62% higher “insulating index number” and 36% lower mass ablation and erosion rates under a standard test with a heat flux of 2500 kW/m2 for 15 s.

  1. Nifurtimox activation by trypanosomal type I nitroreductases generates cytotoxic nitrile metabolites.

    Science.gov (United States)

    Hall, Belinda S; Bot, Christopher; Wilkinson, Shane R

    2011-04-15

    The prodrug nifurtimox has been used for more than 40 years to treat Chagas disease and forms part of a recently approved combinational therapy that targets West African trypanosomiasis. Despite this, its mode of action is poorly understood. Detection of reactive oxygen and nitrogen intermediates in nifurtimox-treated extracts led to the proposal that this drug induces oxidative stress in the target cell. Here, we outline an alternative mechanism involving reductive activation by a eukaryotic type I nitroreductase. Several enzymes proposed to metabolize nifurtimox, including prostaglandin F2α synthase and cytochrome P450 reductase, were overexpressed in bloodstream-form Trypanosoma brucei. Only cells with elevated levels of the nitroreductase displayed altered susceptibility to this nitrofuran, implying a key role in drug action. Reduction of nifurtimox by this enzyme was shown to be insensitive to oxygen and yields a product characterized by LC/MS as an unsaturated open-chain nitrile. This metabolite was shown to inhibit both parasite and mammalian cell growth at equivalent concentrations, in marked contrast to the parental prodrug. These experiments indicate that the basis for the selectivity of nifurtimox against T. brucei lies in the expression of a parasite-encoded type I nitroreductase.

  2. Nifurtimox Activation by Trypanosomal Type I Nitroreductases Generates Cytotoxic Nitrile Metabolites*

    Science.gov (United States)

    Hall, Belinda S.; Bot, Christopher; Wilkinson, Shane R.

    2011-01-01

    The prodrug nifurtimox has been used for more than 40 years to treat Chagas disease and forms part of a recently approved combinational therapy that targets West African trypanosomiasis. Despite this, its mode of action is poorly understood. Detection of reactive oxygen and nitrogen intermediates in nifurtimox-treated extracts led to the proposal that this drug induces oxidative stress in the target cell. Here, we outline an alternative mechanism involving reductive activation by a eukaryotic type I nitroreductase. Several enzymes proposed to metabolize nifurtimox, including prostaglandin F2α synthase and cytochrome P450 reductase, were overexpressed in bloodstream-form Trypanosoma brucei. Only cells with elevated levels of the nitroreductase displayed altered susceptibility to this nitrofuran, implying a key role in drug action. Reduction of nifurtimox by this enzyme was shown to be insensitive to oxygen and yields a product characterized by LC/MS as an unsaturated open-chain nitrile. This metabolite was shown to inhibit both parasite and mammalian cell growth at equivalent concentrations, in marked contrast to the parental prodrug. These experiments indicate that the basis for the selectivity of nifurtimox against T. brucei lies in the expression of a parasite-encoded type I nitroreductase. PMID:21345801

  3. X-ray spectroscopy of nitrile hydratase at pH 7 and 9

    Energy Technology Data Exchange (ETDEWEB)

    Scarrow, R.C.; Duong, D.J.; Kindt, J.T. [Haverford College, PA (United States)] [and others

    1996-08-06

    The iron K-edge X-ray absorption spectrum of Rhodococcus sp. R312 (formerly Brevibacterium sp. R312) nitrile hydratase in frozen solutions at pH 7 and 9 has been analyzed to determine details of the iron coordination. EXAFS analysis implies two or three sulfur ligands per iron and overall six coordination; together with previous EPR and ENDOR results, this implies an N{sub 3}S{sub 2}O ligation sphere. The bond lengths from EXAFS analysis [r{sub av}(Fe-S) = 2.21 {angstrom} at pH 7.3; r{sub av}(Fe-N/O) = 1.99 {angstrom}] support cis coordination of two cysteine ligands and conclusively rule out nitric oxide coordination to the iron, a possibility proposed on the basis of an FTIR difference experiment. The higher-frequency EXAFS can be simulated well by inclusion of multiple scattering from two or three imidazole ligands; the fit to the data is improved if first-sphere multiple scattering pathways are also included. A slight shortening (by 0.02 {plus_minus} 0.01 {angstrom}) of one or both Fe-S bonds when the pH is raised from 7.3 to 9.0 is consistent with shifts observed in the Raman spectrum. 67 refs., 4 figs., 4 tabs.

  4. Towards more thermally stable Li-ion battery electrolytes with salts and solvents sharing nitrile functionality

    Science.gov (United States)

    Kerner, Manfred; Lim, Du-Hyun; Jeschke, Steffen; Rydholm, Tomas; Ahn, Jou-Hyeon; Scheers, Johan

    2016-11-01

    The overall safety of Li-ion batteries is compromised by the state-of-the-art electrolytes; the thermally unstable lithium salt, lithium hexafluorophosphate (LiPF6), and flammable carbonate solvent mixtures. The problem is best addressed by new electrolyte compositions with thermally robust salts in low flammability solvents. In this work we introduce electrolytes with either of two lithium nitrile salts, lithium 4,5-dicyano-1,2,3-triazolate (LiDCTA) or lithium 4,5-dicyano-2-trifluoromethylimidazolide (LiTDI), in solvent mixtures with high flashpoint adiponitrile (ADN), as the main component. With sulfolane (SL) and ethylene carbonate (EC) as co-solvents the liquid temperature range of the electrolytes are extended to lower temperatures without lowering the flashpoint, but at the expense of high viscosities and moderate ionic conductivities. The anodic stabilities of the electrolytes are sufficient for LiFePO4 cathodes and can be charged/discharged for 20 cycles in Li/LiFePO4 cells with coulombic efficiencies exceeding 99% at best. The excellent thermal stabilities of the electrolytes with the solvent combination ADN:SL are promising for future electrochemical investigations at elevated temperatures (> 60 °C) to compensate the moderate transport properties and rate capability. The electrolytes with EC as a co-solvent, however, release CO2 by decomposition of EC in presence of a lithium salt, which potentially makes EC unsuitable for any application targeting higher operating temperatures.

  5. Do clinical examination gloves provide adequate electrical insulation for safe hands-on defibrillation? I: Resistive properties of nitrile gloves.

    Science.gov (United States)

    Deakin, Charles D; Lee-Shrewsbury, Victoria; Hogg, Kitwani; Petley, Graham W

    2013-07-01

    Uninterrupted chest compressions are a key factor in determining resuscitation success. Interruptions to chest compression are often associated with defibrillation, particularly the need to stand clear from the patient during defibrillation. It has been suggested that clinical examination gloves may provide adequate electrical resistance to enable safe hands-on defibrillation in order to minimise interruptions. We therefore examined whether commonly used nitrile clinical examination gloves provide adequate resistance to current flow to enable safe hands-on defibrillation. Clinical examination gloves (Kimberly Clark KC300 Sterling nitrile) worn by members of hospital cardiac arrest teams were collected immediately following termination of resuscitation. To determine the level of protection afforded by visually intact gloves, electrical resistance across the glove was measured by applying a DC voltage across the glove and measuring subsequent resistance. Forty new unused gloves (control) were compared with 28 clinical (non-CPR) gloves and 128 clinical (CPR) gloves. One glove in each group had a visible tear and was excluded from analysis. Control gloves had a minimum resistance of 120 kΩ (median 190 kΩ) compared with 60 kΩ in clinical gloves (both CPR (median 140 kΩ) and non-CPR groups (median 160 kΩ)). Nitrile clinical examination gloves do not provide adequate electrical insulation for the rescuer to safely undertake 'hands-on' defibrillation and when exposed to the physical forces of external chest compression, even greater resistive degradation occurs. Further work is required to identify gloves suitable for safe use for 'hands-on' defibrillation. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Unearthing the mechanism of prebiotic nitrile bond reduction in hydrogen cyanide through a curious association of two molecular radical anions.

    Science.gov (United States)

    Banerjee, Ambar; Ganguly, Gaurab; Tripathi, Ravi; Nair, Nisanth N; Paul, Ankan

    2014-05-19

    HCN is clearly associated with the prebiotic chemical evolution of life. It has been known for decades that the radiolysis of HCN solutions produces sugars, amino acids and nucleobases. Remarkably, recent experimental studies have shown that the photolytic reduction of aqueous HCN by a photoredox reagent [Cu(CN)3](2-) specifically yields sugars, which are the essential building blocks of RNA. Although a mechanistic understanding of such reductions with solvated electrons is poor, the general consensus is that they involve neutral free radicals. We show herein through the use of electronic structure studies and molecular simulations that the reduction of the nitrile bond of HCN is initiated through the formation of a molecular dipole-bound anion from the photoredox reagent. Our theoretical studies show how HCN binds to the photoexcited reagent and then extracts an electron from the reagent and is ultimately detached as a dipole-bound anion. The dipole-bound anionic form of [HCN](-) can easily convert into a solvated valence-bound form of [HCN](-). After the formation of solvated [HCN](-), an extraordinary chemical event ensues through a counter-intuitive coupling of two valence-bound anions to form a solvated molecular dianionic intermediate, [HCN]2(2-). Finally, a proton-coupled electron transfer occurs within the dianionic entity to complete the reduction. This mechanistic scenario is applicable to the reduction of other prebiotic nitrile species and avoids neutral radical-based pathways, thereby preventing the proliferation of reactive species and preserving chemical selectivity. Furthermore, we show how such similar nitrile reduction pathways operate to yield the sugar precursors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. In situ generation of nitrilium from nitrile ylide and the subsequent Mumm rearrangement: copper-catalyzed synthesis of unsymmetrical diacylglycine esters.

    Science.gov (United States)

    Chen, Jijun; Shao, Ying; Ma, Liang; Ma, Meihua; Wan, Xiaobing

    2016-12-07

    A novel in situ generation of nitrilium from a nitrile ylide and the subsequent Mumm rearrangement of carboxylic acid, nitrile, and diazo compounds gave various unsymmetrical diacylglycine esters in moderate to high yields. This copper-catalyzed cascade reaction enables one-pot generation of two C-N bonds, one C[double bond, length as m-dash]O bond, and one C-H bond, with nitrogen as the only byproduct. The reaction has a broad functional-group tolerance, is rapid, easily scales up to the 100 mmol scale, and is insensitive to air and moisture.

  8. An efficient one-pot three-component synthesis of α-amino nitriles via Strecker reaction catalysed by bismuth(III nitrate

    Directory of Open Access Journals (Sweden)

    S. Sheik Mansoor

    2016-09-01

    Full Text Available A convenient and efficient one-pot method for the synthesis of a variety of α-amino nitriles from aldehydes, amines and trimethylsilyl cyanide (TMSCN in the presence of a catalytic amount of Bi(NO33 at room temperature in acetonitrile (MeCN is described. The significant features of this method are simple work-up procedure, inexpensive and non-toxic catalyst, shorter reaction times and excellent product yields. The catalyst Bi(NO33 can be reused. The reusability of the catalyst has been studied for the synthesis of various amino nitriles.

  9. Identification of dipeptidyl nitriles as potent and selective inhibitors of cathepsin B through structure-based drug design.

    Science.gov (United States)

    Greenspan, P D; Clark, K L; Tommasi, R A; Cowen, S D; McQuire, L W; Farley, D L; van Duzer, J H; Goldberg, R L; Zhou, H; Du, Z; Fitt, J J; Coppa, D E; Fang, Z; Macchia, W; Zhu, L; Capparelli, M P; Goldstein, R; Wigg, A M; Doughty, J R; Bohacek, R S; Knap, A K

    2001-12-20

    Cathepsin B is a member of the papain superfamily of cysteine proteases and has been implicated in the pathology of numerous diseases, including arthritis and cancer. As part of an effort to identify potent, reversible inhibitors of this protease, we examined a series of dipeptidyl nitriles, starting with the previously reported Cbz-Phe-NH-CH(2)CN (19, IC(50) = 62 microM). High-resolution X-ray crystallographic data and molecular modeling were used to optimize the P(1), P(2), and P(3) substituents of this template. Cathepsin B is unique in its class in that it contains a carboxylate recognition site in the S(2)' pocket of the active site. Inhibitor potency and selectivity were enhanced by tethering a carboxylate functionality from the carbon alpha to the nitrile to interact with this region of the enzyme. This resulted in the identification of compound 10, a 7 nM inhibitor of cathepsin B, with excellent selectivity over other cysteine cathepsins.

  10. Prebiotic synthesis of 2-deoxy-d-ribose from interstellar building blocks promoted by amino esters or amino nitriles.

    Science.gov (United States)

    Steer, Andrew M; Bia, Nicolas; Smith, David K; Clarke, Paul A

    2017-09-25

    Understanding the prebiotic genesis of 2-deoxy-d-ribose, which forms the backbone of DNA, is of crucial importance to unravelling the origins of life, yet remains open to debate. Here we demonstrate that 20 mol% of proteinogenic amino esters promote the selective formation of 2-deoxy-d-ribose over 2-deoxy-d-threopentose in combined yields of ≥4%. We also demonstrate the first aldol reaction promoted by prebiotically-relevant proteinogenic amino nitriles (20 mol%) for the enantioselective synthesis of d-glyceraldehyde with 6% ee, and its subsequent conversion into 2-deoxy-d-ribose in yields of ≥ 5%. Finally, we explore the combination of these two steps in a one-pot process using 20 mol% of an amino ester or amino nitrile promoter. It is hence demonstrated that three interstellar starting materials, when mixed together with an appropriate promoter, can directly lead to the formation of a mixture of higher carbohydrates, including 2-deoxy-d-ribose.

  11. Redox-Neutral α-Arylation of Alkyl Nitriles with Aryl Sulfoxides: A Rapid Electrophilic Rearrangement.

    Science.gov (United States)

    Shang, Li; Chang, Yonghui; Luo, Fan; He, Jia-Ni; Huang, Xin; Zhang, Lei; Kong, Lichun; Li, Kaixiao; Peng, Bo

    2017-03-22

    A facile α-arylation of nitriles has been developed by simply introducing Tf2O and DABCO to the mixture of nitriles and aryl sulfoxides. The transformation consists of two sequential steps: (i) Tf2O-initiated electrophilic assembly and and (ii) DABCO-triggered rearrangement. Each step can be tuned independently by changing the temperature and/or base. This adjustability allows the method to accommodate a wide range of substrates. Notable features of this new protocol include remarkable efficiency (20 min, -30 °C), exclusive regioselectivity, and high functional group compatibility, which can be challenging issues in traditional approaches. NMR studies not only identified a unique, highly unstable sulfonium imine complex but also demonstrated the importance of temperature in the formation and manipulation of this key intermediate. Further DFT calculations suggested that an electrophilic assembly, followed by removal of HOTf (by base), and finally [3,3]-sigmatropic rearrangement are three key stages in the reaction. The versatile transformability of the products and easy scalability of this reaction are also exhibited here.

  12. Mapping Vinyl Cyanide and Other Nitriles in Titan’s Atmosphere Using ALMA

    Energy Technology Data Exchange (ETDEWEB)

    Lai, J. C.-Y.; Cordiner, M. A.; Nixon, C. A.; Achterberg, R. K.; Molter, E. M.; Palmer, M. Y.; Charnley, S. B.; Lindberg, J. E.; Mumma, M. J. [NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Teanby, N. A. [School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol, BS8 1RJ (United Kingdom); Kisiel, Z. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikøw 32/46, 02-668 Warszawa (Poland); Irwin, P. G. J., E-mail: martin.cordiner@nasa.gov [Atmospheric, Oceanic and Planetary Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford, OX1 3PU (United Kingdom)

    2017-11-01

    Vinyl cyanide (C{sub 2}H{sub 3}CN) is theorized to form in Titan’s atmosphere via high-altitude photochemistry and is of interest regarding the astrobiology of cold planetary surfaces due to its predicted ability to form cell membrane-like structures (azotosomes) in liquid methane. In this work, we follow up on the initial spectroscopic detection of C{sub 2}H{sub 3}CN on Titan by Palmer et al. with the detection of three new C{sub 2}H{sub 3}CN rotational emission lines at submillimeter frequencies. These new, high-resolution detections have allowed for the first spatial distribution mapping of C{sub 2}H{sub 3}CN on Titan. We present simultaneous observations of C{sub 2}H{sub 5}CN, HC{sub 3}N, and CH{sub 3}CN emission, and obtain the first (tentative) detection of C{sub 3}H{sub 8} (propane) at radio wavelengths. We present disk-averaged vertical abundance profiles, two-dimensional spatial maps, and latitudinal flux profiles for the observed nitriles. Similarly to HC{sub 3}N and C{sub 2}H{sub 5}CN, which are theorized to be short-lived in Titan’s atmosphere, C{sub 2}H{sub 3}CN is most abundant over the southern (winter) pole, whereas the longer-lived CH{sub 3}CN is more concentrated in the north. This abundance pattern is consistent with the combined effects of high-altitude photochemical production, poleward advection, and the subsequent reversal of Titan’s atmospheric circulation system following the recent transition from northern to southern winter. We confirm that C{sub 2}H{sub 3}CN and C{sub 2}H{sub 5}CN are most abundant at altitudes above 200 km. Using a 300 km step model, the average abundance of C{sub 2}H{sub 3}CN is found to be 3.03 ± 0.29 ppb, with a C{sub 2}H{sub 5}CN/C{sub 2}H{sub 3}CN abundance ratio of 2.43 ± 0.26. Our HC{sub 3}N and CH{sub 3}CN spectra can be accurately modeled using abundance gradients above the tropopause, with fractional scale-heights of 2.05 ± 0.16 and 1.63 ± 0.02, respectively.

  13. Mapping Vinyl Cyanide and Other Nitriles in Titan’s Atmosphere Using ALMA

    Science.gov (United States)

    Lai, J. C.-Y.; Cordiner, M. A.; Nixon, C. A.; Achterberg, R. K.; Molter, E. M.; Teanby, N. A.; Palmer, M. Y.; Charnley, S. B.; Lindberg, J. E.; Kisiel, Z.; Mumma, M. J.; Irwin, P. G. J.

    2017-11-01

    Vinyl cyanide (C2H3CN) is theorized to form in Titan’s atmosphere via high-altitude photochemistry and is of interest regarding the astrobiology of cold planetary surfaces due to its predicted ability to form cell membrane-like structures (azotosomes) in liquid methane. In this work, we follow up on the initial spectroscopic detection of C2H3CN on Titan by Palmer et al. with the detection of three new C2H3CN rotational emission lines at submillimeter frequencies. These new, high-resolution detections have allowed for the first spatial distribution mapping of C2H3CN on Titan. We present simultaneous observations of C2H5CN, HC3N, and CH3CN emission, and obtain the first (tentative) detection of C3H8 (propane) at radio wavelengths. We present disk-averaged vertical abundance profiles, two-dimensional spatial maps, and latitudinal flux profiles for the observed nitriles. Similarly to HC3N and C2H5CN, which are theorized to be short-lived in Titan’s atmosphere, C2H3CN is most abundant over the southern (winter) pole, whereas the longer-lived CH3CN is more concentrated in the north. This abundance pattern is consistent with the combined effects of high-altitude photochemical production, poleward advection, and the subsequent reversal of Titan’s atmospheric circulation system following the recent transition from northern to southern winter. We confirm that C2H3CN and C2H5CN are most abundant at altitudes above 200 km. Using a 300 km step model, the average abundance of C2H3CN is found to be 3.03 ± 0.29 ppb, with a C2H5CN/C2H3CN abundance ratio of 2.43 ± 0.26. Our HC3N and CH3CN spectra can be accurately modeled using abundance gradients above the tropopause, with fractional scale-heights of 2.05 ± 0.16 and 1.63 ± 0.02, respectively.

  14. Effect of physicochemical parameters on nitrile-hydrolyzing potentials of newly isolated nitrilase of Fusarium oxysporum f. sp. lycopercisi ED-3.

    Science.gov (United States)

    Bura Gohain, Manorama; Talukdar, Shruti; Talukdar, Madhumita; Yadav, Archana; Gogoi, Binod Kumar; Bora, Tarun Chandra; Kiran, Shashi; Gulati, Arvind

    2015-01-01

    In recent years, nitrilases from fungus have received increasing attention, and most of the studies are performed on nitrilases of bacterial origin. Frequently used methods are based on analytical methods such as high-performance liquid chromatography, liquid chromatography-mass spectrometry, and gas chromatography; therefore, an efficient, user friendly, and rapid method has been developed to screen nitrilase enzyme based on the principle of color change of a pH indicator. Phenol red amended with the minimal medium appears light yellow at neutral pH, which changes into pink with the formation of ammonia, indicating nitrilase activity in the reaction medium. A highly potent strain ED-3 identified as Fusarium oxysporum f. sp. lycopercisi (specific activity 17.5 µmol/Min/mg dcw) was isolated using this method. The nitrilase activity of F. oxysporum f. sp. lycopercisi ED-3 strain showed wide substrate specificity toward aliphatic nitriles, aromatic nitriles, and orthosubstituted heterocyclic nitriles. 4-Aminobenzonitrile was found to be a superior substrate among all the nitriles used in this study. This nitrilase was active within pH 5-10 and temperature ranging from 25 to 60 °C with optimal at pH 7.0 and temperature at 50 °C. The nitrilase activity was enhanced to several folds through optimization of culture and biotransformation conditions from 1,121 to 1,941 µmol/Min. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

  15. Bio-Inspired Nitrile Hydration by Peptidic Ligands Based on L-Cysteine, L-Methionine or L-Penicillamine and Pyridine-2,6-dicarboxylic Acid

    Directory of Open Access Journals (Sweden)

    Cillian Byrne

    2014-12-01

    Full Text Available Nitrile hydratase (NHase, EC 4.2.1.84 is a metalloenzyme which catalyses the conversion of nitriles to amides. The high efficiency and broad substrate range of NHase have led to the successful application of this enzyme as a biocatalyst in the industrial syntheses of acrylamide and nicotinamide and in the bioremediation of nitrile waste. Crystal structures of both cobalt(III- and iron(III-dependent NHases reveal an unusual metal binding motif made up from six sequential amino acids and comprising two amide nitrogens from the peptide backbone and three cysteine-derived sulfur ligands, each at a different oxidation state (thiolate, sulfenate and sulfinate. Based on the active site geometry revealed by these crystal structures, we have designed a series of small-molecule ligands which integrate essential features of the NHase metal binding motif into a readily accessible peptide environment. We report the synthesis of ligands based on a pyridine-2,6-dicarboxylic acid scaffold and L-cysteine, L-S-methylcysteine, L-methionine or L-penicillamine. These ligands have been combined with cobalt(III and iron(III and tested as catalysts for biomimetic nitrile hydration. The highest levels of activity are observed with the L-penicillamine ligand which, in combination with cobalt(III, converts acetonitrile to acetamide at 1.25 turnovers and benzonitrile to benzamide at 1.20 turnovers.

  16. Nanocomposites of nitrile (NBR) rubber with multi-walled carbon nanotubes

    Science.gov (United States)

    Warasitthinon, Nuthathai

    Nanotechnology offers the promise of creating new materials with enhanced performance. There are different kinds of fillers used in rubber nanocomposites, such as carbon black, silica, carbon fibers, and organoclays. Carbon nanotube reinforced elastomers have potential for improved rubber properties in aggressive environments. The first chapter is an introduction to the literature. The second chapter investigated the incorporation of multi-walled carbon nanotubes (MWCNTs) into rubber matrix for potential use in high temperature applications. The vulcanization kinetics of acrylonitrile butadiene rubber (NBR) reinforced with multi-walled carbon nanotubes was investigated. The vulcanized NBR rubber with different loading percentages of MWCNTs was also compared to NBR reinforced with carbon black N330. The optimum curing time at 170°C (T90) was found to decrease with increasing content of MWCNTs. Increased filler loading of both carbon black and MWCNTs gave higher modulus and strength. The MWCNTs filled materials gave better retention of modulus and tensile strength at high temperatures, but lower strength as compared to the carbon black filled samples. In the third chapter, carbon black (CB, 50phr) content in nitrile rubber (NBR) nanocomposites was partially replaced by multi-walled carbon nanotubes (MWCNTs). NBR/CB/CNTs nanocomposites with varying ratio of CB/CNTs (50/0 phr to 40/10 phr) were formulated via the melt-mixing method using an internal mixer. The reinforcing effect of single filler (CB) and mixture of fillers (CB and CNTs) on the properties of NBR nanocomposites was investigated. The cure kinetics and bound rubber content were analyzed using rheometry and solvent swelling method. In addition, mechanical behavior at both room temperature and high temperature (350°F/ 121°C) were examined. The scorch time and curing time values showed that there was no significant effect on the curing behavior of NBR nanocomposites after the partial replacement of CB with

  17. Studies on gel electrolyte based on nitrile-butadiene copolymers. Final report, 1 November 1991-30 November 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sircar, A.K.; Kumar, B.; Linden, S.M.; Weissman, P.T.

    1993-06-01

    This study is concerned with the preparation of a hybrid electrolyte, suitable for solid-polymer batteries. Based on the study of ionic conductivity in the presence of LiBF4 of a number of nitrile-butadiene copolymers (NBR), hydrogenated NBR (HNBR) was selected as the host polymer. DC conductivity studies with three different lithium salts in different plasticizers showed the highest conductivity for LiBF4. Conductivity of LiBF4 in different plasticizers decreases in the order DMF > DMAC > Gamma butyrolactone > NMP > PC=gamma-valerolactone > glymes. NMP was chosen as the plasticizer for hybrid films based on its moderate conductivity, low vapor pressure, and low freezing point. Polymer electrolytes, Gel electrolytes, Ionic conductivity.

  18. Density functional theory and quantum mechanics/molecular mechanics study of cysteine protease inhibition by nitrile-based inhibitors.

    Science.gov (United States)

    De Visser, Sam; Quesne, Matthew; Ward, Richard

    2013-12-01

    Cysteine protease enzymes are important for human physiology and catalyze key protein degradation pathways. These enzymes react via a nucleophilic reaction mechanism that involves a cysteine residue and the proton of a proximal histidine. Particularly efficient inhibitors of these enzymes are nitrile-based, however, the details of the catalytic reaction mechanism currently are poorly understood. To gain further insight into the inhibition of these molecules, we have performed a combined density functional theory and quantum mechanics/molecular mechanics study on the reaction of a nitrile-based inhibitor with the enzyme active site amino acids. We show here that small perturbations to the inhibitor structure can have dramatic effects on the catalysis and inhibition processes. Thus, we investigated a range of inhibitor templates and show that specific structural changes reduce the inhibitory efficiency by several orders of magnitude. Moreover, as the reaction takes place on a polar surface, we find strong differences between the DFT and QM/MM calculated energetics. In particular, the DFT model led to dramatic distortions from the starting structure and the convergence to a structure that would not fit the enzyme active site. In the subsequent QM/MM study we investigated the use of mechanical versus electronic embedding on the kinetics, thermodynamics and geometries along the reaction mechanism. We find minor effects on the kinetics of the reaction but large geometric and thermodynamics differences as a result of inclusion of electronic embedding corrections. The work here highlights the importance of model choice in the investigation of this biochemical reaction mechanism.

  19. Induction and suppression of herbivore-induced indirect defenses

    NARCIS (Netherlands)

    Alba, J.M.; Allmann, S.; Glas, J.J.; Schimmel, B.C.J.; Spyropoulou, E.A.; Stoops, M.; Villaroel, C.; Kant, M.R.; Witzany, G.; Baluška, F.

    2012-01-01

    Plants release volatiles into the air. Upon herbivory, the amounts they release from the vegetative tissues increases dramatically. Although the physiological necessity for this increased emission is not fully understood, it has interesting consequences, the most important one being that foraging

  20. Catalytic Hydrogen Production by Ruthenium Complexes from the Conversion of Primary Amines to Nitriles: Potential Application as a Liquid Organic Hydrogen Carrier.

    Science.gov (United States)

    Ventura-Espinosa, David; Marzá-Beltrán, Aida; Mata, Jose A

    2016-12-05

    The potential application of the primary amine/nitrile pair as a liquid organic hydrogen carrier (LOHC) has been evaluated. Ruthenium complexes of formula [(p-cym)Ru(NHC)Cl2 ] (NHC=N-heterocyclic carbene) catalyze the acceptorless dehydrogenation of primary amines to nitriles with the formation of molecular hydrogen. Notably, the reaction proceeds without any external additive, under air, and under mild reaction conditions. The catalytic properties of a ruthenium complex supported on the surface of graphene have been explored for reutilization purposes. The ruthenium-supported catalyst is active for at least 10 runs without any apparent loss of activity. The results obtained in terms of catalytic activity, stability, and recyclability are encouraging for the potential application of the amine/nitrile pair as a LOHC. The main challenge in the dehydrogenation of benzylamines is the selectivity control, such as avoiding the formation of imine byproducts due to transamination reactions. Herein, selectivity has been achieved by using long-chain primary amines such as dodecylamine. Mechanistic studies have been performed to rationalize the key factors involved in the activity and selectivity of the catalysts in the dehydrogenation of amines. The experimental results suggest that the catalyst resting state contains a coordinated amine. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Preparation and dual microwave-absorption properties of carboxylic poly(arylene ether nitrile)/Fe{sub 3}O{sub 4} hybrid microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Ma Zhen; Meng Fanbin; Zhao Rui; Zhan Yingqing; Zhong Jiachun [Research Branch of Advanced Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); Liu Xiaobo, E-mail: Liuxb@uestc.edu.cn [Research Branch of Advanced Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2012-04-15

    The carboxylic poly(arylene ether nitrile)/Fe{sub 3}O{sub 4} hybrid microspheres were prepared via solvothermal method. The carboxylic poly(arylene ether nitrile) (PEN-COOH) was introduced into the Fe{sub 3}O{sub 4} microspheres by chemisorption with mass content up to 15% as defined by infrared spectra and thermal gravimetric analysis. The hybrid sphere is of hierarchical polymer-inorganic microstructure as observed by transmission electron microscopy. The microwave-absorption of the sample owns a shifting peak and a special immobilized peak with the variation of absorber thickness from 3 to 5 mm. Maximum microwave-absorption of the product is capable of over -30 dB in the range of 10-12 GHz. By proposed equivalent filter circuit model, the immobilized peak was attributed to the ordered nanostructure where the Fe{sub 3}O{sub 4} nanocrystals were isolated by PEN-COOH. The product has the potential to be applied as microwave absorber with high microwave-absorption, good dispersibility and robust polymer-inorganic interfacial adherence. - Highlights: Black-Right-Pointing-Pointer We prepared poly(arylene ether nitrile)/Fe{sub 3}O{sub 4} hybrid microspheres with hierarchical polymer-inorganic nanostructure. Black-Right-Pointing-Pointer A shifting and an immobilized microwave absorbing peaks were observed on the sample. Black-Right-Pointing-Pointer Possible mechanism was proposed on the basis of electromagnetic data.

  2. Effect of multiple alcohol-based hand rub applications on the tensile properties of thirteen brands of medical exam nitrile and latex gloves.

    Science.gov (United States)

    Gao, Pengfei; Horvatin, Matthew; Niezgoda, George; Weible, Robyn; Shaffer, Ronald

    2016-12-01

    Current CDC guidance for the disinfection of gloved hands during the doffing of personal protective equipment (PPE) following the care of a patient with Ebola recommends for multiple applications of alcohol-based hand rub (ABHR) on medical exam gloves. To evaluate possible effects of ABHR applications on glove integrity, thirteen brands of nitrile and latex medical exam gloves from five manufacturers and two different ABHRs were included in this study. A pair of gloves were worn by a test operator and the outside surfaces of the gloves were separately treated with an ABHR for 1-6 applications. Tensile strength and ultimate elongation of the gloves without any ABHR treatments (control gloves) and gloves after 1-6 ABHR applications were measured based on the ASTM D412 standard method. In general, tensile strength decreased with each ABHR application. ABHRs had more effect on the tensile strength of the tested nitrile than latex gloves, while ethanol-based ABHR (EBHR) resulted in lesser changes in tensile strength compared to isopropanol-based ABHR (IBHR). The results show that multiple EBHR applications on the latex gloves and some of the nitrile gloves tested should be safe for Ebola PPE doffing based on the CDC guidance. Appropriate hospital staff practice using ABHR treatment and doffing gloves is recommended to become more familiar with changes in glove properties.

  3. A novel strategy for acetonitrile wastewater treatment by using a recombinant bacterium with biofilm-forming and nitrile-degrading capability.

    Science.gov (United States)

    Li, Chunyan; Yue, Zhenlei; Feng, Fengzhao; Xi, Chuanwu; Zang, Hailian; An, Xuejiao; Liu, Keran

    2016-10-01

    There is a great need for efficient acetonitrile removal technology in wastewater treatment to reduce the discharge of this pollutant in untreated wastewater. In this study, a nitrilase gene (nit) isolated from a nitrile-degrading bacterium (Rhodococcus rhodochrous BX2) was cloned and transformed into a biofilm-forming bacterium (Bacillus subtilis N4) that expressed the recombinant protein upon isopropylthio-β-galactoside (IPTG) induction. The recombinant bacterium (B. subtilis N4-pHT01-nit) formed strong biofilms and had nitrile-degrading capability. Further testing demonstrated that biofilms formed by B. subtilis N4-pHT01-nit were highly resistant to loading shock from acetonitrile and almost completely degraded the initial concentration of acetonitrile (800 mg L(-1)) within 24 h in a moving bed biofilm reactor (MBBR) after operation for 35 d. The bacterial composition of the biofilm, identified by high-throughput sequencing, in a reactor in which the B. subtilis N4-pHT01-nit bacterium was introduced indicated that the engineered bacterium was successfully immobilized in the reactor and became dominant genus. This work demonstrates that an engineered bacterium with nitrile-degrading and biofilm-forming capacity can improve the degradation of contaminants in wastewater. This approach offers a novel strategy for enhancing the biological oxidation of toxic pollutants in wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. The Stability Enhancement of Nitrile Hydratase from Bordetella petrii by Swapping the C-terminal Domain of β subunit.

    Science.gov (United States)

    Sun, Weifeng; Zhu, Longbao; Chen, Xianggui; Wu, Lunjie; Zhou, Zhemin; Liu, Yi

    2016-04-01

    The thermal stability of most nitrile hydratases (NHase) is poor, which has been enhanced to some extent by molecular modifications in several specific regions of the C-terminal domain (C-domain) of β subunit of NHase. Since the C-domain could be present as a naturally separate domain in a few NHases, the whole C-domain is proposed to be related to the NHase stability. The chimeric NHase (SBpNHase) from the thermal-sensitive BpNHase (NHase from Bordetella petrii) and the relatively thermal-stable PtNHase (NHase from Pseudonocardia thermophila) was constructed by swapping the corresponding C-domains. After 30 min incubation at 50 °C, the original BpNHase nearly lost its activity, while the SBpNHase retained 50 % residual activity, compared with the melting temperature (Tm) (50 °C) of the original BpNHase, that of the SBpNHase was 55 °C. The SBpNHase with higher thermal stability would be useful for the thermal stability enhancement of NHase and for the understanding of the relationship between the stability of NHase and its structure.

  5. Successful expression of the Bordetella petrii nitrile hydratase activator P14K and the unnecessary role of Ser115.

    Science.gov (United States)

    Sun, Weifeng; Zhu, Longbao; Chen, Xianggui; Chen, Ping; Yang, Lingling; Ding, Wenwu; Zhou, Zhemin; Liu, Yi

    2016-02-20

    The activator P14K is necessary for the activation of nitrile hydratase (NHase). However, it is hard to be expressed heterogeneously. Although an N-terminal strep tagged P14K could be successfully expressed from Pseudomonas putida, various strategies for the over-expression of P14K are needed to facilitate further application of NHase. P14K was successfully expressed through fusing a his tag (his-P14K), and was over-expressed through fusing a gst tag (gst-P14K) at its N-terminus in the NHase of Bordetella petrii DSM 12804. The stability of gst-P14K was demonstrated to be higher than that of the his-P14K. In addition, the Ser115 in the characteristic motif CXLC-Ser115-C of the active center of NHase was found to be unnecessary for NHase maturation. Our results are not only useful for the NHase activator expression and the understanding of the role of Ser115 during NHase activation, but also helpful for other proteins with difficulty in heterologous expression.

  6. Thermomechanical properties of zirconium tungstate/hydrogenated nitrile butadiene rubber (HNBR) composites for low-temperature applications

    Science.gov (United States)

    Akulichev, Anton G.; Alcock, Ben; Tiwari, Avinash; Echtermeyer, Andreas T.

    2016-12-01

    Rubber compounds for pressure sealing application typically have inferior dimensional stability with temperature fluctuations compared with their steel counterparts. This effect may result in seal leakage failures when subjected to decreases in temperature. Composites of hydrogenated nitrile butadiene rubber (HNBR) and zirconium tungstate as a negative thermal expansion filler were prepared in order to control the thermal expansivity of the material. The amount of zirconium tungstate (ZrW2O8) was varied in the range of 0 to about 40 vol%. The coefficient of thermal expansion (CTE), bulk modulus, uniaxial extension and compression set properties were measured. The CTE of the ZrW2O8-filled HNBR decreases with the filler content and it is reduced by a factor of 2 at the highest filler concentration used. The filler effect on CTE is found to be stronger when HNBR is below the glass transition temperature. The experimental thermal expansion data of the composites are compared with the theoretical estimates and predictions given by FEA. The effect of ZrW2O8 on the mechanical characteristics and compression set of these materials is also discussed.

  7. The improvement of the mechanical properties of PMMA denture base by Al2O3 particles with nitrile rubber

    Science.gov (United States)

    Alhareb, Ahmed Omran; Akil, Hazizan Md; Ahmad, Zainal Arifin

    2017-07-01

    Poly methyl methacrylate (PMMA) is mostly used for fabrication of denture base by heat-curing technique. Therefore, the purpose of this study is to investigate the effect of Al2O3 filler as toughening particles together with nitrile butadiene rubber (NBR) particles as impact modifier were used to reinforce PMMA denture base materials on the impact strength (IS) and fracture toughness (KIC). PMMA powder was mixed with liquid methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. The powder components are PMMA, benzoyl peroxide, NBR (5, 7.5 and 10 wt%), and Al2O3 filler (5 wt%) treated by silane. The liquid components are 90% of methyl methacrylate and 10 % ethylene glycol dimethacryate. FTIR analyses confirmed that the Al2O3 filler was successfully treated with silane as coupling agent. The morphology of fracture surfaces was characterized using field emission scanning electron microscopy (FESEM). The results shown that IS and KIC improved significantly when using treated the Al2O3 filler. IS has increased to 56% (8.26 KJ/m2) and 73% (2.77 MPa.m1/2) for KIC when treated Al2O3 filler compared to unreinforced PMMA matrix. Statistical analyses of data results were significantly improved (P<0.05) when using 7.5 wt% NBR with treated Al2O3 filler compared to other the compositions.

  8. Influence of gamma irradiation on mechanical and thermal properties of waste polyethylene/nitrile butadiene rubber blend

    Directory of Open Access Journals (Sweden)

    Raouf O. Aly

    2016-11-01

    Full Text Available Gamma irradiation radical–radical interaction crosslinking of elastomers and thermoplastic is a special type of crosslinking technique that has gained importance over conventional chemical crosslinking method as process is fast, pollution free, and simple. In this work a blend polymer, based on waste polyethylene and nitrile butadiene rubber, has been irradiated with gamma-rays, mechanically and thermally investigated at varying NBR content. FTIR and SEM techniques were used in addition to the swelling behavior to emphasize the blend formation. Mechanical properties like tensile strength, elongation at break and modulus at different elongations were studied and compared with those of unirradiated ones. A relatively low-radiation dose was found effective in improving the level of mechanical properties. Differential scanning calorimeter and thermogravimetric analysis were used to study the thermal characteristics of the irradiated polymer. Enhancement in thermal stability has been observed for higher NBR containing blends and via radiation-induced crosslinking up to ≈50 kGy.

  9. Spectroscopic and theoretical evidence for the photoinduced twisted intramolecular charge transfer state formation in N,N-dimethylaminonaphthyl-(acrylo)-nitrile

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Rupashree Balia; Mahanta, Subrata; Kar, Samiran [Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009 (India); Guchhait, Nikhil [Department of Chemistry, University of Calcutta, 92, A. P. C. Road, Kolkata 700009 (India)], E-mail: nikhil.guchhait@rediffmail.com

    2008-09-15

    The phenomenon of excited state twisted intramolecular charge transfer (TICT) process in N,N-dimethylaminonaphthyl-(acrylo)-nitrile (DMANAN) has been reported on the basis of steady-state absorption and fluorescence spectroscopy in combination with quantum chemical calculations. The absorption and fluorescence characteristics of DMANAN in solvents of different polarity reveal the presence of a single species in the ground state which forms the intramolecular charge transfer state upon photoexcitation. The observed dual fluorescence is assigned to a high-energy emission from the locally excited or the Franck-Condon state and the red-shifted emission from the charge transfer (CT) state. In polar protic solvents, hydrogen-bonding interaction on CT emission has been established from the linear dependency of the position of the low-energy emission maxima on hydrogen-bonding parameter ({alpha}). The experimental findings have been correlated with the theoretical results based on TICT model obtained at density functional theory (DFT) level. The theoretical potential energy surface for the first excited state along both the donor and acceptor twist coordinates in the gas phase obtained by time dependent density functional theory (TDDFT) method and in polar solvent by time dependent density functional theory-polarized continuum model (TDDFT-PCM) method predicts well the experimental spectral properties.

  10. Wear resistance and friction reduction in acrylo nitrile butadiene rubber through hybrid combination of graphite flakes and nano tungsten disulphide

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Neha, E-mail: neha87bhu@gmail.com [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India); Pandey, Akanksha; Parihar, A. S.; Mishra, A. K.; Mukhopadhyay, K.; Prasad, N. E. [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Gandhi, M. N.; Bhattacharyya, A. R. [Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India)

    2016-05-06

    Friction and wear have considerable role in the life span of two interacting parts. Incorporation of nanofillers in polymers/elastomers matrix causes commendable changes in its tribologicalproperties. The main purpose of this work is to reduce the coefficient of friction and wear rate of Acrylo Nitrile Butadiene rubber (NBR). To achieve such objective traditionally well knownlubricants graphite(G), tungsten disulphide (WS{sub 2}) and there hybrid combination was incorporated in NBR matrix. Effect of applied load (force) and concentration of fillers on tribological properties of NBR had been studied. The filler incorporation enhanced the hardnessby 8%, showed resistance to hydraulic oil and aging effect also got improved significantly. A particular optimized concentration of NBR with hybrid combination of 2% WS{sub 2} and 4% Graphite showed minimum coefficient of friction as well as wear rate. A hypothesis could be attributed that similar lamellar structure of WS{sub 2} and Graphite along with formation of a stable nanoscale disulfide tribofilmcould result in lowering of friction. These substantially improved properties of nanoreinforced rubber materials would definitely pave promising path for plethora of potential technological applications.

  11. Development and validation of an automated monitoring system for oxygenated volatile organic compounds and nitrile compounds in ambient air.

    Science.gov (United States)

    Roukos, J; Plaisance, H; Leonardis, T; Bates, M; Locoge, N

    2009-12-04

    Few studies were conducted on oxygenated volatile organic compounds (OVOC) because of problems encountered during the sampling/analyzing steps induced by water in sampled air. Consequently, there is a lack of knowledge of their spatial and temporal trends and their origins in ambient air. In this study, an analyzer consisted of a thermal desorber (TD) interfaced with a gas chromatograph (GC) and a flame ionization detector (FID) was developed for online measurements of 18 OVOC in ambient air including 4 alcohols, 6 aldehydes, 3 ketones, 3 ethers, 2 esters and 4 nitriles. The main difficulty was to overcome the humidity effect without loss of compounds. Water amount in the sampled air was reduced by the trap composition (two hydrophobic graphitized carbons-Carbopack B:Carbopack X), the trap temperature (held at 12.5 degrees C), by diluting (50:50) the sample with dry air before the preconcentration step and a trap purge with helium. Humidity management allowed the use of a polar CP-Lowox column in order to separate the polar compounds from the hydrocarbon/aromatic matrix. The safe sampling volume for the dual-sorbent trap 75 mg Carbopack X:5mg Carbopack B was found to 405 mL for ethanol by analyzing a standard mixture at a relative humidity of 80%. Detection limits ranging from 10 ppt for ETBE to 90 ppt for ethanol were obtained for 18 compounds for a sampling volume of 405 mL. Good repeatabilities were obtained at two levels of concentration (relative standard deviation vehicles while acetone has a different temporal evolution that can be probably associated with remote sources.

  12. Effect of magnetic and thermal properties of iron oxide nanoparticles (IONs) in nitrile butadiene rubber (NBR) latex

    Science.gov (United States)

    Ong, Hun Tiar; Julkapli, Nurhidayatullaili Muhd; Hamid, Sharifah Bee Abd; Boondamnoen, O.; Tai, Mun Foong

    2015-12-01

    Nitrile butadiene rubber (NBR) gloves are one of the most important personal protective equipments but they are possible to tear off and contaminate food or pharmaceutical and healthcare products during manufacturing and packaging process. High tendency of torn glove remaining in food or products due to white or light flesh-coloured glove is not easy to be detected by naked eyes. In this paper, iron oxide nanoparticles (IONs) selected as additive for NBR to improve its detectability by mean of magnetic properties. IONs synthesized via precipitation method and compounded with NBR latex before casting on petri dish. The properties of IONs were investigated by X-ray Diffractometry (XRD), Transmission Electron Microscope (TEM), Raman Spectroscopy and Vibrating Sample Magnetometer (VSM). Meanwhile NBR/IONs composites were studied by Thermogravimetry Analysis (TGA), Differential Scanning Calorimetry (DSC) and Vibrating Sample Magnetometer (VSM). It observed that, synthesized IONs shows of 25.28 nm crystallite with 25.86 nm semipherical (changed as) shape. Meanwhile, Magnetite and maghemite phase are found in range of 670 cm-1 and 700 cm-1 respectively, which it contributes magnetization saturation of 73.96 emu/g at 10,000 G by VSM. Thermal stability and magnetic properties were increased with incorporating IONs into NBR latex up to 20 phr. NBR/IONs 5 phr has the optimum thermal stability, lowest glass transition temperature (-14.83 °C) and acceptable range of magnetization saturation (3.83 emu/g at 10,000 G) to form NBR gloves with magnetic detectability.

  13. One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

    Directory of Open Access Journals (Sweden)

    Roman Yu. Peshkov

    2016-07-01

    Full Text Available A convenient one-pot approach to alkylcyanobiaryls is described. The method is based on biaryl cross-coupling between the sodium salt of the terephthalonitrile dianion and a neutral aromatic nitrile in liquid ammonia, and successive alkylation of the long-lived anionic intermediate with alkyl bromides. The reaction is compatible with benzonitriles that contain methyl, methoxy and phenyl groups, fluorine atoms, and a 1-cyanonaphthalene residue. The variety of ω-substituted alkyl bromides, including an extra bromine atom, a double bond, cyano and ester groups, as well as a 1,3-dioxane fragment are suitable as alkylation reagents.

  14. The use of styrene-butadiene rubber waste as a potential filler in nitrile rubber: order of addition and size of waste particles

    OpenAIRE

    Baeta,D. A.; Zattera,J. A.; Oliveira,M. G.; Oliveira,P. J.

    2009-01-01

    Styrene-butadiene rubber (SBR) has large applications in the shoe industry, especially as expanded sheets used to produce insoles and inner soles. According to TG analysis, the rubber content in SBR residues (SBR-r) was found to be around 26-wt%. Based on that data, a cost-effective technique for the reuse of SBR-r in Nitrile rubber (NBR) was developed. Later, the effect of SBR-r on the cure behavior, mechanical performance, swelling, and crosslink density of reused rubber was investigated, w...

  15. Effect of magnetic and thermal properties of iron oxide nanoparticles (IONs) in nitrile butadiene rubber (NBR) latex

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Hun Tiar; Julkapli, Nurhidayatullaili Muhd; Hamid, Sharifah Bee Abd, E-mail: sharifahbee@um.edu.my; Boondamnoen, O.; Tai, Mun Foong

    2015-12-01

    Nitrile butadiene rubber (NBR) gloves are one of the most important personal protective equipments but they are possible to tear off and contaminate food or pharmaceutical and healthcare products during manufacturing and packaging process. High tendency of torn glove remaining in food or products due to white or light flesh-coloured glove is not easy to be detected by naked eyes. In this paper, iron oxide nanoparticles (IONs) selected as additive for NBR to improve its detectability by mean of magnetic properties. IONs synthesized via precipitation method and compounded with NBR latex before casting on petri dish. The properties of IONs were investigated by X-ray Diffractometry (XRD), Transmission Electron Microscope (TEM), Raman Spectroscopy and Vibrating Sample Magnetometer (VSM). Meanwhile NBR/IONs composites were studied by Thermogravimetry Analysis (TGA), Differential Scanning Calorimetry (DSC) and Vibrating Sample Magnetometer (VSM). It observed that, synthesized IONs shows of 25.28 nm crystallite with 25.86 nm semipherical (changed as) shape. Meanwhile, Magnetite and maghemite phase are found in range of 670 cm{sup −1} and 700 cm{sup −1} respectively, which it contributes magnetization saturation of 73.96 emu/g at 10,000 G by VSM. Thermal stability and magnetic properties were increased with incorporating IONs into NBR latex up to 20 phr. NBR/IONs 5 phr has the optimum thermal stability, lowest glass transition temperature (−14.83 °C) and acceptable range of magnetization saturation (3.83 emu/g at 10,000 G) to form NBR gloves with magnetic detectability. - Highlights: • We synthesized IONs with high magnetization saturation (M{sub s}). • High M{sub s} of IONs were incorporated into NBR latex in order to induce magnetic properties in the NBR composite. • Introduction of IONs into NBR latex would improve thermal properties. • The produced NBR/IONs 5 phr composite exceeded the minimum magnetic moment sensor of the detector. • They have high

  16. Nitrile/Buna N Material Failure Assessment for an O-Ring used on the Gaseous Hydrogen Flow Control Valve (FCV) of the Space Shuttle Main Engine

    Science.gov (United States)

    Wingard, Doug

    2006-01-01

    After the rollout of Space Shuttle Discovery in April 2005 in preparation for return-to-flight, there was a failure of the Orbiter (OV-103) helium signature leak test in the gaseous hydrogen (GH2) system. Leakage was attributed to the Flow Control Valve (FCV) in Main Engine 3. The FCV determined to be the source of the leak for OV-103 is designated as LV-58. The nitrile/Buna N rubber O-ring seal was removed from LV-58, and failure analysis indicated radial cracks providing leak paths in one quadrant. Cracks were eventually found in 6 of 9 FCV O-rings among the three Shuttle Orbiters, though none were as severe as those for LV-58, OV-103. Testing by EM10 at MSFC on all 9 FCV O- rings included: laser dimensional, Shore A hardness and properties from a dynamic mechanical analyzer (DMA) and an Instron tensile machine. The following test data was obtained on the cracked quadrant of the LV-58, OV-103 O-ring: (1) the estimated compression set was only 9.5%, compared to none for the rest of the O-ring; (2) Shore A hardness for the O.D. was higher by almost 4 durometer points than for the rest of the O-ring; and (3) DMA data showed that the storage/elastic modulus E was almost 25% lower than for the rest of the O-ring. Of the 8 FCV O-rings tested on an Instron, 4 yielded tensile strengths that were below the MIL spec requirement of 1350 psi-a likely influence of rubber cracking. Comparisons were made between values of modulus determined by DNA (elastic) and Instron (Young s). Each nitrile/Buna N O-ring used in the FCV conforms to the MIL-P-25732C specification. A number of such O-rings taken from shelf storage at MSFC and Kennedy Space Center (KSC) were used to generate a reference curve of DMA glass transition temperature (Tg) vs. shelf storage time ranging from 8 to 26 years. A similar reference curve of TGA onset temperature (of rubber weight loss) vs. shelf storage time was also generated. The DMA and TGA data for the used FCV O-rings were compared to the reference

  17. The Soleil View on Prototypical Organic Nitriles: Selected Vibrational Modes of Ethyl Cyanide, C_2H_5CN, and Spectroscopic Analysis Using AN Automated Spectral Assignment Procedure (asap)

    Science.gov (United States)

    Endres, Christian; Caselli, Paola; Martin-Drumel, Marie-Aline; McCarthy, Michael C.; Pirali, Olivier; Wehres, Nadine; Schlemmer, Stephan; Thorwirth, Sven

    2016-06-01

    Vibrational spectra of small organic nitriles, propionitrile and n-butyronitrile, have been investigated at high spectral resolution at the French national synchroton facility SOLEIL using Fourier-transform far-infrared spectroscopy (< 700 cm-1). The Automated Spectral Assignment Procedure (ASAP) has been used for line assignement and accurate determination of rotational level energies, in particular, of the ν20=1 and the ν12=1 states of propionitrile. The analysis does not only confirm the applicability of the ASAP in the treatment of (dense) high-resolution infrared spectra but also reveals some of its limitations which will be discussed in some detail. M. A. Martin-Drumel, C. P. Endres, O. Zingsheim, T. Salomon, J. van Wijngaarden, O. Pirali, S. Gruet, F. Lewen, S. Schlemmer, M. C. McCarthy, and S. Thorwirth 2015, J. Mol. Spectrosc. 315, 72

  18. Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

    Energy Technology Data Exchange (ETDEWEB)

    Razavizadeh, Mahmoud; Jamshidi, Masoud, E-mail: mjamshidi@iust.ac.ir

    2016-08-30

    Highlights: • In this research UV-irradiated PET fabric was chemically modified. • The fabric at first carboxylated under UV irradiation using glutaric anhydride, then it was grafted using isocyanate (i.e. MDI). • The surface of the fabric was characterized before and after each treating satge. • The composite samples were prepared and tested for T-Peel test. The surfaces of the fabrics were surface characterized to understand. - Abstract: Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

  19. Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles.

    Science.gov (United States)

    Zhang, Song-Lin; Deng, Zhu-Qin

    2016-07-26

    A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions.

  20. Adhesion of nitrile rubber (NBR) to polyethylene terephthalate (PET) fabric. Part 1: PET surface modification by methylenediphenyl di-isocyanate (MDI)

    Energy Technology Data Exchange (ETDEWEB)

    Razavizadeh, Mahmoud; Jamshidi, Masoud, E-mail: mjamshidi@iust.ac.ir

    2016-01-01

    Graphical abstract: - Highlights: • Glutaric anhydride peroxide (GAP) was grafted on PET surface by UV irradiation method. Then MDI was attached to GAP on PET surface. • The fabric was vulcanized by nitrile rubber. • Peet test was performed after each stage of surface modification. • Curing temperature was increased and the tests were repeated. • Effect of MDI coating on PET without carboxylation was evaluated. Effect of vulcanizing temperature on this product was also studied. - Abstract: Fiber to rubber adhesion is an important subject in rubber composite industry. It is well known that surface physical, mechanical and chemical treatments are effective methods to improve interfacial bonding. Ultra violet (UV) light irradiation is an efficient method which is used to increase interfacial interactions. In this research UV assisted chemical modification of PET fabric was used to increase its bonding to nitrile rubber (NBR). NBR is perfect selection to produce fuel and oil resistant rubber parts but it has weak bonding to fabrics. For this purpose at first, the PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was reacted and grafted to carboxylated PET. T-peel test was used to evaluate PET fabric to NBR bonding strength. Attenuated total reflectance-Fourier transform infrared spectroscopy (FTIR-AT) was used to assess surface modifications of the PET fabrics. The chemical composition of the PET surfaces before and after carboxylation and MDI grafting was investigated by X-ray photoelectron spectroscopy (XPS). It was found that at vulcanizing temperature of 150 °C, carboxylation in contrary to MDI grafting, improved considerably PET to NBR adhesion. Finally effect of curing temperature on PET to NBR bonding strength was determined. It was found that increasing vulcanizing temperature to 170 °C caused considerable improvement (about 134%) in bonding strength.

  1. An Ultra-Performance Liquid Chromatoghraphy-Tandem Mass Spectrometry (UPLC-MS/MS) Method for the Rapid and Sensitive Determination of Sulforaphane and Sulforaphane Nitrile in Brassica Vegetables

    OpenAIRE

    Alvarez Jubete, Laura; Smyth, Thomas J.; Valverde, Juan; Rai, Dilip K.; Barry-Ryan, Catherine

    2013-01-01

    A rapid UPLC-MS/MS method has been developed and validated for the simultaneous analysis of sulforaphane and sulforaphane nitrile from Brassica Oleracea L. This method was developed utilising an Acquity BEH C8 column with gradient elution combined with tandem mass spectrometry detection, using positive ion electrospray ionisation in multiple reaction monitoring (MRM) mode. The method was validated for linearity, sensitivity, precision, accuracy, matrix effects and recovery. The retention time...

  2. Combined experimental and theoretical studies of regio- and stereoselectivity in reactions of β-isoxazolyl- and β-imidazolyl enamines with nitrile oxides

    Directory of Open Access Journals (Sweden)

    Ilya V. Efimov

    2016-11-01

    Full Text Available Reactions of β-azolyl enamines and nitrile oxides were studied by both experimental and theoretical methods. (E-β-(4-Nitroimidazol-5-yl, (5-nitroimidazol-4-yl and isoxazol-5-yl enamines smoothly react regioselectively at room temperature in dioxane solution with aryl, pyridyl, and cyclohexylhydroxamoyl chlorides without a catalyst or a base to form 4-azolylisoxazoles as the only products in good yields. The intermediate 4,5-dihydroisoxazolines were isolated as trans isomers during the reaction of (E-β-imidazol-4-yl enamines with aryl and cyclohexylhydroxamoyl chlorides. Stepwise and concerted pathways for the reaction of β-azolyl enamines with hydroxamoyl chlorides were considered and studied at the B3LYP/Def2-TZVP level of theory combined with D3BJ dispersion correction. The reactions of benzonitrile oxide with both E- and Z-imidazolyl enamines have been shown to proceed stereoselectively to form trans- and cis-isoxazolines, respectively. The preference of E-isomers over Z-isomers, driven by the higher stability of the former, apparently controls the stereoselectivity of the investigated cycloaddition reaction with benzonitrilе oxide. Based on the reactivity of azolyl enamines towards hydroxamoyl chlorides, a novel, effective catalyst-free method was elaborated to prepare 4-azolyl-5-substituted isoxazoles that are otherwise difficult to obtain.

  3. Novel proton exchange membranes based on cardo poly(arylene ether sulfone/nitrile)s with perfluoroalkyl sulfonic acid moieties for passive direct methanol fuel cells

    Science.gov (United States)

    Zheng, Jifu; He, Qingyi; Gao, Nian; Yuan, Ting; Zhang, Suobo; Yang, Hui

    2014-09-01

    A new series of cardo poly(arylene ether sulfone/nitrile)s FSPES-x with perfluoroalkyl sulfonic acid groups have been successfully prepared by the perfluorosulfonic acid lactone ring-opening reaction without using any metal or base catalysts. These materials have been characterized by IR, NMR and TGA. The results indicate that this simple and metal-free method of preparation is highly efficient for controlling both the degree of perfluorosulfonation and the position of the sulfonate group and no side reactions such as crosslinking is observed. The FSPES-x membranes (IEC = 1.17-1.64 m equiv g-1) show the desired characteristics such as good film-forming ability, excellent thermal and mechanical properties, low methanol permeability, high conductivity (up to 0.083 S cm-1 at room temperature), as well as appropriate cell performance compared to Nafion®117. With these properties, such fluorinated sulfonic acid side-chain-type polymers are promising PEM materials for application in fuel cells.

  4. Partial conversion of thioamide into nitrile in a copper(II) complex of 2,6-diacetylpyridine bis(thiosemicarbazone), a drug prototype for Alzheimer's disease.

    Science.gov (United States)

    Vieira, Rafael P; Thompson, John R; Beraldo, Heloisa; Storr, Tim

    2015-06-01

    This work reports the crystal structure of [(Z)-2-((E)-1-{6-[1-({[amino(sulfanidyl-κS)methylidene]amino}imino-κN)ethyl]pyridin-2-yl-κN}ethylidene)-1-cyanohydrazinido-κN(1)]copper(II), [Cu(C11H11N7S)], the first description of a copper(II) complex of 2,6-diacetylpyridine bis(thiosemicarbazone) showing partial conversion of a thioamide group to a nitrile group. The asymmetric ligand coordinates to the metal centre in an N,N',N'',S-tetradentate manner via the pyridine N atom, an imine N atom, the hydrazinide N atom and the sulfanidyl S atom, displaying a square-planar geometry. Ligand coordination results in two five-membered chelate rings and one six-membered chelate ring, and in crystal packing based on N-H···N hydrogen bonds of the cyanohydrazinide and hydrazinecarbothioamidate arms of the ligand. The correlation between the partial conversion upon metal complexation, H2S release and possible effects on the activity of bis(thiosemicarbazone)s as drug prototypes for Alzheimer's disease is also discussed.

  5. Composites Based on Core-Shell Structured HBCuPc@CNTs-Fe3O4 and Polyarylene Ether Nitriles with Excellent Dielectric and Mechanical Properties

    Science.gov (United States)

    Pu, Zejun; Zhong, Jiachun; Liu, Xiaobo

    2017-10-01

    Core-shell structured magnetic carbon nanotubes (CNTs-Fe3O4) coated with hyperbranched copper phthalocyanine (HBCuPc) (HBCuPc@CNTs-Fe3O4) hybrids were prepared by the solvent-thermal method. The results indicated that the HBCuPc molecules were decorated on the surface of CNTs-Fe3O4 through coordination behavior of phthalocyanines, and the CNTs-Fe3O4 core was completely coaxial wrapped by a functional intermediate HBCuPc shell. Then, polymer-based composites with a relatively high dielectric constant and low dielectric loss were fabricated by using core-shell structured HBCuPc@CNTs-Fe3O4 hybrids as fillers and polyarylene ether nitriles (PEN) as the polymer matrix. The cross-sectional scanning electron microscopy (SEM) images of composites showed that there is almost no agglomeration and internal delamination. In addition, the rheological analysis reveals that the core-shell structured HBCuPc@CNTs-Fe3O4 hybrids present better dispersion and stronger interface adhesion with the PEN matrix than CNTs-Fe3O4, thus resulting in significant improvement of the mechanical, thermal and dielectric properties of polymer-based composites.

  6. Unprecedented Nucleophilic Additions of Highly Polar Organometallic Compounds to Imines and Nitriles Using Water as a Non-Innocent Reaction Medium.

    Science.gov (United States)

    Dilauro, Giuseppe; Dell'Aera, Marzia; Vitale, Paola; Capriati, Vito; Perna, Filippo Maria

    2017-08-14

    In contrast to classic methods carried out under inert atmospheres with dry volatile organic solvents and often low temperatures, the addition of highly polar organometallic compounds to non-activated imines and nitriles proceeds quickly, efficiently, and chemoselectively with a broad range of substrates at room temperature and under air with water as the only reaction medium. Secondary amines and tertiary carbinamines are furnished in yields of up to and over 99 %. The significant solvent D/H isotope effect observed for the on-water nucleophilic additions of organolithium compounds to imines suggests that the on-water catalysis arises from proton transfer across the organic-water interface. The strong intermolecular hydrogen bonds between water molecules may play a key role in disfavoring protonolysis, which occurs extensively in other protic media such as methanol. This work lays the foundation for reshaping many fundamental s-block metal-mediated organic transformations in water. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The use of styrene-butadiene rubber waste as a potential filler in nitrile rubber: order of addition and size of waste particles

    Directory of Open Access Journals (Sweden)

    D. A. Baeta

    2009-03-01

    Full Text Available Styrene-butadiene rubber (SBR has large applications in the shoe industry, especially as expanded sheets used to produce insoles and inner soles. According to TG analysis, the rubber content in SBR residues (SBR-r was found to be around 26-wt%. Based on that data, a cost-effective technique for the reuse of SBR-r in Nitrile rubber (NBR was developed. Later, the effect of SBR-r on the cure behavior, mechanical performance, swelling, and crosslink density of reused rubber was investigated, with more emphasis placed on the effect of both particle size and loading of waste filler. Cure characteristics such as optimum cure time and scorch time were then reduced by the increasing amount of SBR-r filler. Owing to the reinforced nature of the largest particle size SBR-r, the best results for the mechanical properties of NBR were those in which SBR-r was added at the end of the cure process. The study has thus shown that SBR residue (SBR-r can be used as an economical alternative filler in NBR.

  8. Country-wide distribution of the nitrile female condom (FC2) in Brazil and South Africa: a cost-effectiveness analysis.

    Science.gov (United States)

    Dowdy, David W; Sweat, Michael D; Holtgrave, David R

    2006-10-24

    To evaluate the cost-effectiveness and potential impact of expanded female condom distribution. Cost-effectiveness analysis assessing HIV infections averted annually and incremental cost per HIV infection averted for country-wide distribution of the nitrile female condom (FC2) among sexually active individuals, 15-49 years, with access to publicly distributed condoms in Brazil and South Africa. In Brazil, expansion of FC2 distribution to 10% of current male condom use would avert an estimated 604 (5-95th percentiles, 412-831) HIV infections at 20,683 US dollars (5-95th percentiles, 13,497-29,521) per infection averted. In South Africa, 9577 (5-95th percentiles, 6539-13,270) infections could be averted, at 985 US dollars (5-95th percentiles, 633-1412) per infection averted. The estimated cost of treating one HIV-infected individual is 21,970 US dollars (5-95th percentiles, 18,369-25,719) in Brazil and 1503 US dollars (5-95th percentiles, 1245-1769) in South Africa, indicating potential cost savings. The incremental cost of expanded distribution would be reduced to 8930 US dollars (5-95th percentiles, 5864-13,163) per infection averted in Brazil and 374 US dollars (5-95th percentiles, 237-553) in South Africa by acquiring FC2s through a global purchasing mechanism and increasing distribution threefold. Sensitivity analyses show model estimates to be most sensitive to the estimated prevalence of sexually transmitted infections, total sexual activity, and fraction of FC2s properly used. Expanded distribution of FC2 in Brazil and South Africa could avert substantial numbers of HIV infections at little or no net cost to donor or government agencies. FC2 may be a useful and cost-effective supplement to the male condom for preventing HIV.

  9. bis-Nitrile and bis-Dialkylcyanamide Platinum(II Complexes as Efficient Catalysts for Hydrosilylation Cross-Linking of Siloxane Polymers

    Directory of Open Access Journals (Sweden)

    Regina M. Islamova

    2016-03-01

    Full Text Available cis- and trans-Isomers of the platinum(II nitrile complexes [PtCl2(NCR2] (R = NMe2, N(C5H10, Ph, CH2Ph were examined as catalysts for hydrosilylation cross-linking of vinyl-terminated polydimethylsiloxane and trimethylsilyl-terminated poly(dimethylsiloxane-co-ethylhydrosiloxane producing high quality silicone rubbers. Among the tested platinum species the cis-complexes are much more active catalysts than their trans-congeners and for all studied platinum complexes cis-[PtCl2(NCCH2Ph2] exhibits the best catalytic activity (room temperature, c = 1.0 × 10−4 mol/L, τpot-life 60 min, τcuring 6 h. Although cis-[PtCl2(NCCH2Ph2] is less active than the widely used Karstedt’s catalyst, its application for the cross-linking can be performed not only at room temperature (c = 1.0 × 10−4 mol/L, but also, more efficiently, at 80 °C (c = 1.0 × 10−4–1.0 × 10−5 mol/L and it prevents adherence of the formed silicone rubbers to equipment. The usage of the cis- and trans-[PtCl2(NCR2] complexes as the hydrosilylation catalysts do not require any inhibitors and, moreover, the complexes and their mixtures with vinyl- and trimethylsilyl terminated polysiloxanes are shelf-stable in air. Tested catalysts do not form colloid platinum particles after the cross-linking.

  10. OLT1177, a β-sulfonyl nitrile compound, safe in humans, inhibits the NLRP3 inflammasome and reverses the metabolic cost of inflammation.

    Science.gov (United States)

    Marchetti, Carlo; Swartzwelter, Benjamin; Gamboni, Fabia; Neff, Charles P; Richter, Katrin; Azam, Tania; Carta, Sonia; Tengesdal, Isak; Nemkov, Travis; D'Alessandro, Angelo; Henry, Curtis; Jones, Gerald S; Goodrich, Scott A; St Laurent, Joseph P; Jones, Terry M; Scribner, Curtis L; Barrow, Robert B; Altman, Roy D; Skouras, Damaris B; Gattorno, Marco; Grau, Veronika; Janciauskiene, Sabina; Rubartelli, Anna; Joosten, Leo A B; Dinarello, Charles A

    2018-02-13

    Activation of the NLRP3 inflammasome induces maturation of IL-1β and IL-18, both validated targets for treating acute and chronic inflammatory diseases. Here, we demonstrate that OLT1177, an orally active β-sulfonyl nitrile molecule, inhibits activation of the NLRP3 inflammasome. In vitro, nanomolar concentrations of OLT1177 reduced IL-1β and IL-18 release following canonical and noncanonical NLRP3 inflammasome activation. The molecule showed no effect on the NLRC4 and AIM2 inflammasomes, suggesting specificity for NLRP3. In LPS-stimulated human blood-derived macrophages, OLT1177 decreased IL-1β levels by 60% and IL-18 by 70% at concentrations 100-fold lower in vitro than plasma concentrations safely reached in humans. OLT1177 also reduced IL-1β release and caspase-1 activity in freshly obtained human blood neutrophils. In monocytes isolated from patients with cryopyrin-associated periodic syndrome (CAPS), OLT1177 inhibited LPS-induced IL-1β release by 84% and 36%. Immunoprecipitation and FRET analysis demonstrated that OLT1177 prevented NLRP3-ASC, as well as NLRP3-caspase-1 interaction, thus inhibiting NLRP3 inflammasome oligomerization. In a cell-free assay, OLT1177 reduced ATPase activity of recombinant NLRP3, suggesting direct targeting of NLRP3. Mechanistically, OLT1177 did not affect potassium efflux, gene expression, or synthesis of the IL-1β precursor. Steady-state levels of phosphorylated NF-κB and IkB kinase were significantly lowered in spleen cells from OLT1177-treated mice. We observed reduced IL-1β content in tissue homogenates, limited oxidative stress, and increased muscle oxidative metabolism in OLT1177-treated mice challenged with LPS. Healthy humans receiving 1,000 mg of OLT1177 daily for 8 d exhibited neither adverse effects nor biochemical or hematological changes. Copyright © 2018 the Author(s). Published by PNAS.

  11. Constitutive and herbivore-induced volatiles in pear, alder and hawthorn trees

    NARCIS (Netherlands)

    Scutareanu, P.; Bruin, de J.; Posthumus, M.A.; Drukker, B.

    2003-01-01

    Qualitative and quantitative differences among pear cultivars were found in constitutive and Cacopsylla-induced volatiles, depending on experimental treatment of the trees (i.e., uninfested and partly or completely infested by psyllids). Blend differences were also found between pear cultivars and

  12. Herbivore-induced plant volatiles mediate in-flight host discrimination by parasitoids

    NARCIS (Netherlands)

    Fatouros, N.E.; van Loon, J.J.A.; Hordijk, C.A.; Smid, H.M.; Dicke, M.

    2005-01-01

    Herbivore feeding induces plants to emit volatiles that are detectable and reliable cues for foraging parasitoids, which allows them to perform oriented host searching. We investigated whether these plant volatiles play a role in avoiding parasitoid competition by discriminating parasitized from

  13. Specificity of herbivore-induced responses in an invasive species, Alternanthera philoxeroides (alligator weed).

    Science.gov (United States)

    Liu, Mu; Zhou, Fang; Pan, Xiaoyun; Zhang, Zhijie; Traw, Milton B; Li, Bo

    2018-01-01

    Herbivory-induced responses in plants can both negatively affect subsequently colonizing herbivores and mitigate the effect of herbivory on the host. However, it is still less known whether plants exhibit specific responses to specialist and generalist herbivores in non-secondary metabolite traits and how specificity to specialists and generalists differs between invasive and native plant populations. We exposed an invasive plant, Alternanthera philoxeroides, to Agasicles hygrophila (Coleoptera, Chrysomelidae; specialist), Spodoptera litura (Lepidoptera, Noctuidae; generalist), manual clipping, or application of exogenous jasmonic acid and examined both the specificity of elicitation in traits of fitness (e.g., aboveground biomass), morphology (e.g., root:shoot ratio), and chemistry (e.g., C/N ratio and lignin), and specificity of effect on the subsequent performance of A. hygrophila and S. litura. Then, we assessed variation of the specificity between invasive and native populations (USA and Argentina, respectively). The results showed S. litura induced higher branching intensity and specific leaf area but lower C/N ratio than A. hygrophila, whereas A. hygrophila induced higher trichome density than S. litura. The negative effect of induction on subsequent larval growth was greater for S. litura than for A. hygrophila. Invasive populations had a weaker response to S. litura than to A. hygrophila in triterpenoid saponins and C/N ratio, while native populations responded similarly to these two herbivores. The specific effect on the two herbivores feeding on induced plants did not vary between invasive and native populations. Overall, we demonstrate specificity of elicitation to specialist and generalist herbivores in non-secondary metabolite traits, and that the generalist is more susceptible to induction than the specialist. Furthermore, chemical responses specific to specialist and generalist herbivores only exist in the invasive populations, consistent with an evolutionary change in specificity in the invasive populations.

  14. Elevated carbon dioxide reduces emission of herbivore induced volatiles in Zea mays

    Science.gov (United States)

    Terpene volatiles produced by sweet corn (Zea mays) upon infestation with pests such as beet armyworm (Spodoptera exigua) function as part of an indirect defense mechanism by attracting parasitoid wasps; yet little is known about the impact of atmospheric changes on this form of plant defense. To in...

  15. Powdery mildew suppresses herbivore-induced plant volatiles and interferes with parasitoid attraction in Brassica rapa

    Science.gov (United States)

    The co-occurrence of different antagonists on a plant can greatly affect infochemicals with ecological consequences for higher trophic levels. Here we investigated how the presence of a plant pathogen, the powdery mildew Erysiphe cruciferarum, on Brassica rapa affects 1) plant volatiles emitted in r...

  16. Birds exploit herbivore-induced plant volatiles to locate herbivorous prey.

    Science.gov (United States)

    Amo, Luisa; Jansen, Jeroen J; van Dam, Nicole M; Dicke, Marcel; Visser, Marcel E

    2013-11-01

    Arthropod herbivory induces plant volatiles that can be used by natural enemies of the herbivores to find their prey. This has been studied mainly for arthropods that prey upon or parasitise herbivorous arthropods but rarely for insectivorous birds, one of the main groups of predators of herbivorous insects such as lepidopteran larvae. Here, we show that great tits (Parus major) discriminate between caterpillar-infested and uninfested trees. Birds were attracted to infested trees, even when they could not see the larvae or their feeding damage. We furthermore show that infested and uninfested trees differ in volatile emissions and visual characteristics. Finally, we show, for the first time, that birds smell which tree is infested with their prey based on differences in volatile profiles emitted by infested and uninfested trees. Volatiles emitted by plants in response to herbivory by lepidopteran larvae thus not only attract predatory insects but also vertebrate predators. © 2013 John Wiley & Sons Ltd/CNRS.

  17. Birds exploit herbivore-induced plant volatiles to locate herbivorous prey

    NARCIS (Netherlands)

    Amo, L.; Jansen, J.J.; Van Dam, N.M.; Dicke, M.; Visser, M.E.

    2013-01-01

    Arthropod herbivory induces plant volatiles that can be used by natural enemies of the herbivores to find their prey. This has been studied mainly for arthropods that prey upon or parasitise herbivorous arthropods but rarely for insectivorous birds, one of the main groups of predators of herbivorous

  18. Effect of Drought on Herbivore-Induced Plant Gene Expression: Population Comparison for Range Limit Inferences

    Directory of Open Access Journals (Sweden)

    Gunbharpur Singh Gill

    2016-03-01

    Full Text Available Low elevation “trailing edge” range margin populations typically face increases in both abiotic and biotic stressors that may contribute to range limit development. We hypothesize that selection may act on ABA and JA signaling pathways for more stable expression needed for range expansion, but that antagonistic crosstalk prevents their simultaneous co-option. To test this hypothesis, we compared high and low elevation populations of Boechera stricta that have diverged with respect to constitutive levels of glucosinolate defenses and root:shoot ratios; neither population has high levels of both traits. If constraints imposed by antagonistic signaling underlie this divergence, one would predict that high constitutive levels of traits would coincide with lower plasticity. To test this prediction, we compared the genetically diverged populations in a double challenge drought-herbivory growth chamber experiment. Although a glucosinolate defense response to the generalist insect herbivore Spodoptera exigua was attenuated under drought conditions, the plastic defense response did not differ significantly between populations. Similarly, although several potential drought tolerance traits were measured, only stomatal aperture behavior, as measured by carbon isotope ratios, was less plastic as predicted in the high elevation population. However, RNAseq results on a small subset of plants indicated differential expression of relevant genes between populations as predicted. We suggest that the ambiguity in our results stems from a weaker link between the pathways and the functional traits compared to transcripts.

  19. A solvent free, four-component synthesis and 1,3-dipolar cycloaddition of 4(H)-pyrans with nitrile oxides: synthesis and discovery of antimycobacterial activity of enantiomerically pure 1,2,4-oxadiazoles.

    Science.gov (United States)

    Almansour, Abdulrahman I; Suresh Kumar, Raju; Arumugam, Natarajan; Sriram, Dharmarajan

    2012-07-01

    Four-component reactions of (R)-1-(1-phenylethyl)tetrahydro-4(1H)-pyridinone, aromatic aldehydes and malononitrile in a 1:2:1 molar ratio in the presence of solid sodium ethoxide under solvent free conditions afforded an inseparable mixture of two diastereomeric 4(H)-pyrans in near quantitative yields. These compounds upon 1,3-dipolar cycloaddition with nitrile oxides furnished two enantiomerically pure 1,2,4-oxadiazoles in moderate yields, which were screened for in vitro activity against Mycobacterium tuberculosis H37Rv (MTB) and multi-drug resistant M. tuberculosis (MDR-TB). Among the compounds screened, compound 10h was found to be the most active in vitro with a MIC value of 0.07 and 0.14 μM against MTB and MDR-TB respectively. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  20. Crystal structure of tri­chlorido­(4'-ferrocenyl-2,2':6',2''-terpyridine-[kappa]3N,N',N'')iridium(III) aceto­nitrile disolvate

    KAUST Repository

    Davaasuren, Bambar

    2015-02-25

    In the title compound, [FeIr(C5H5)(C20H14N3)Cl3]·2CH3CN, the central IrIII atom is sixfold coordinated by three chloride ligands and three terpyridine N atoms in a slightly distorted octa­hedral fashion. The terpyridine ligand is functionalized at the 4\\'-position with a ferrocenyl group, the latter being in an eclipsed conformation. In the crystal, mol­ecules are stacked in rows parallel to [001], with the aceto­nitrile solvent mol­ecules situated between the rows. An extensive network of intra- and inter­molecular C-H...Cl inter­actions is present, stabilizing the three-dimensional structure.

  1. P[N(i-Bu)CH(2)CH(2)](3)N: nonionic Lewis base for promoting the room-temperature synthesis of α,β-unsaturated esters, fluorides, ketones, and nitriles using Wadsworth-Emmons phosphonates.

    Science.gov (United States)

    Chintareddy, Venkat Reddy; Ellern, Arkady; Verkade, John G

    2010-11-05

    The bicyclic triaminophosphine P(RNCH(2)CH(2))(3)N (R = i-Bu, 1c) serves as an effective promoter for the room-temperature stereoselective synthesis of α,β-unsaturated esters, fluorides, and nitriles from a wide array of aromatic, aliphatic, heterocyclic, and cyclic aldehydes and ketones, using a range of Wadsworth-Emmons (WE) phosphonates. Among the analogues of 1c [R = Me (1a), i-Pr (1b), Bn (1d)], 1a and 1b performed well, although longer reaction times were involved, and 1d led to poorer yields than 1c. Functionalities such as cyano, chloro, bromo, methoxy, amino, ester, and nitro were well tolerated. We were able to isolate and characterize (by X-ray means; see above) the reactive WE intermediate species formed from 2b and 1c.

  2. Whole glove permeation of cyclohexanol through disposable nitrile gloves on a dextrous robot hand and comparison with the modified closed-loop ASTM F739 method 1. No fist clenching.

    Science.gov (United States)

    Mathews, Airek R; Que Hee, Shane S

    2017-04-01

    The aim was to develop a whole glove permeation method for cyclohexanol to generate permeation parameter data for a non-moving dextrous robot hand (normalized breakthrough time t b , standardized breakthrough time t s , steady state permeation rate P s , and diffusion coefficient D). Four types of disposable powderless, unsupported, and unlined nitrile gloves from the same producer were investigated: Safeskin Blue and Kimtech Science Blue, Purple, and Sterling. The whole glove method developed involved a peristaltic pump for water circulation through chemically resistant Viton tubing to continually wash the inner surface of the test glove via holes in the tubing, a dextrous robot hand operated by a microprocessor, a chemically protective nitrile glove to protect the robot hand, an incubator to maintain 35°C temperature, and a hot plate to maintain 35°C at the sampling point of the circulating water. Aliquots of 1.0 mL were sampled at regular time intervals for the first 60 min followed by removal of 0.5 mL aliquots every hour to 8 hr. Quantification was by the internal standard method after gas chromatography-selective ion electron impact mass spectrometry using a non-polar capillary column. The individual glove values of t b and t s differed for the ASTM closed loop method except for Safeskin Blue, but did not for the whole glove method. Most of the kinetic parameters agreed within an order of magnitude for the two techniques. The order of most protective to least protective glove was Blue and Safeskin, then Purple followed by Sterling for the whole gloves. The analogous order for the modified F739 ASTM closed loop method was: Safeskin, Blue, Purple, and Sterling, almost the same as for the whole glove. The Sterling glove was "not recommended" from the modified ASTM data, and was "poor" from the whole glove data.

  3. Pt(II)-mediated imine-nitrile coupling leading to symmetrical (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato)Pt(II) complexes containing the incorporated 1,3-diiminoisoindoline moiety.

    Science.gov (United States)

    Lasri, Jamal; Kuznetsov, Maxim L; Guedes da Silva, M Fátima C; Pombeiro, Armando J L

    2012-10-15

    Treatment of trans-[PtCl(2)(NCR)(2)] (1; R = Et (1a), Ph (1b)) with 1,3-diiminoisoindoline (2) gives access to the corresponding symmetrical (1,3,5,7,9-pentaazanona-1,3,6,8-tetraenato)Pt(II) complexes [PtCl{NH═C(R)N═C(C(6)H(4))NC═NC(R)═NH}] (3). The reactions of 1 with one equivalent of 1,1,3,3-tetramethylguanidine (4), 1,3-diphenylguanidine (6), or acetone oxime (8) leads to the formation of mixed asymmetrical Pt(II) complexes trans-[PtCl(2){NH═C(R)N═C(NMe(2))(2)}(NCR)] (5), [PtCl{NH═C(R)NC(NHPh)═NPh}(NCR)] (7), or trans-[PtCl(2){NH═C(Ph)ON═CMe(2)}(NCPh)] (9), respectively, as a result of nucleophilic addition to one of the nitrile ligands in 1. Treatment of 5, 7, and 9 with one equivalent of 2 leads to complexes 3. The complexes were characterized by IR, (1)H, (13)C{(1)H}, and (195)Pt NMR (for 3) spectroscopies, ESI(+)-MS, elemental analyses, and X-ray diffraction (for 3). Complex 3a has an asymmetric unit with five independent Pt molecules of the same chemical composition and two molecules of water, resulting in a total of 40 molecules of the complex and sixteen guest water molecules per unit cell. Theoretical calculations revealed that the most plausible mechanism of formation of complexes 3 includes stepwise nucleophilic addition of 2 to one of the nitrile ligands in 1, a first cyclization upon formation of the Pt-N bond and elimination of HCl, and a second nucleophilic addition/cyclization.

  4. fac-[1,2-Bis(pyridin-4-yl)ethane-κN]tricarbon-yl(1,10-phenanthroline-κ(2) N,N')rhenium(I) hexa-fluorido-phosphate aceto-nitrile monosolvate.

    Science.gov (United States)

    Guilardi, Silvana; Patrocinio, Antonio Otavio Toledo; de Sousa, Sinval Fernandes; Ellena, Javier

    2014-07-01

    The asymmetric unit of the title compound, [Re(C12H8N2)(C12H12N2)(CO)3]PF6.·CH3CN, contains one cation, one hexa-fluorido-phosphate anion and one aceto-nitrile solvent mol-ecule. The Re(I) ion is coordinated by two N atoms from the 1,10-phenanthroline ligand and one N atom from the 1,2-bis-(pyridin-4-yl)ethane ligand [mean Re-N = 2.191 (15) Å] and by three carbonyl ligands [mean Re-C = 1.926 (3) Å] in a distorted octa-hedral geometry. The electrostatic forces and weak C-H⋯F(O) hydrogen bonds pack cations and anions into the crystal with voids of 82 Å(3), which are filled by solvent mol-ecules. The crystal packing exhibits short inter-molecular O⋯O distance of 2.795 (5) Å between two cations related by inversion.

  5. fac-[1,2-Bis(pyridin-4-yl)ethane-κN]tricarbon­yl(1,10-phenanthroline-κ2 N,N′)rhenium(I) hexa­fluorido­phosphate aceto­nitrile monosolvate

    Science.gov (United States)

    Guilardi, Silvana; Patrocinio, Antonio Otavio Toledo; de Sousa, Sinval Fernandes; Ellena, Javier

    2014-01-01

    The asymmetric unit of the title compound, [Re(C12H8N2)(C12H12N2)(CO)3]PF6.·CH3CN, contains one cation, one hexa­fluorido­phosphate anion and one aceto­nitrile solvent mol­ecule. The ReI ion is coordinated by two N atoms from the 1,10-phenanthroline ligand and one N atom from the 1,2-bis­(pyridin-4-yl)ethane ligand [mean Re—N = 2.191 (15) Å] and by three carbonyl ligands [mean Re—C = 1.926 (3) Å] in a distorted octa­hedral geometry. The electrostatic forces and weak C—H⋯F(O) hydrogen bonds pack cations and anions into the crystal with voids of 82 Å3, which are filled by solvent mol­ecules. The crystal packing exhibits short inter­molecular O⋯O distance of 2.795 (5) Å between two cations related by inversion. PMID:25161535

  6. High-performance magnetic poly (arylene ether nitrile) nanocomposites: Co-modification of Fe3O4 via mussel inspired poly(dopamine) and amino functionalized silane KH550

    Science.gov (United States)

    Wan, Xinyi; Zhan, Yingqing; Long, Zhihang; Zeng, Guangyong; Ren, Yang; He, Yi

    2017-12-01

    To develop high-performance magnetic polymer composites, we reported a facial mussel-inspired way to functionalize Fe3O4 microspheres with dopamine (DA) and KH550, followed by compounding with poly (arylene ether nitrile) (PEN), to prepare functional nanocomposite films. Such mussel inspired co-modification of Fe3O4 was characterized and confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Therefore, the outstanding properties of the functionalize Fe3O4/polymer composites were obtained. With the addition of 15 wt% functionalized Fe3O4, the saturation magnetization (Ms) and dielectric permittivity of the PEN composites were increased to 12.49 emu/g and 14.3 (250 Hz), respectively, while the low dielectric loss was maintained. In addition, even the high loading content of Fe3O4 was incorporated, the functional PEN composites still exhibited high mechanical properties and thermal stability, including the significant improvement in glass transition temperature, and the same level of the tensile strength compared with neat PEN. Our work revealed that magnetic and dielectric PEN composites materials along with high comprehensive properties may be potentially used in the electromagnetic fields.

  7. Ice chemistry on outer solar system bodies: Carboxylic acids, nitriles, and urea detected in refractory residues produced from the UV photolysis of N{sub 2}:CH{sub 4}:CO-containing ices

    Energy Technology Data Exchange (ETDEWEB)

    Materese, Christopher K.; Cruikshank, Dale P.; Sandford, Scott A.; Imanaka, Hiroshi; Nuevo, Michel [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035-1000 (United States); White, Douglas W. [Jacksonville State University, 700 Pelham Road North, Jacksonville, AL 36265-1602 (United States)

    2014-06-20

    Radiation processing of the surface ices of outer solar system bodies may result in the production of new chemical species even at low temperatures. Many of the smaller, more volatile molecules that are likely produced by the photolysis of these ices have been well characterized by laboratory experiments. However, the more complex refractory material formed in these experiments remains largely uncharacterized. In this work, we present a series of laboratory experiments in which low-temperature (15-20 K) N{sub 2}:CH{sub 4}:CO ices in relative proportions 100:1:1 are subjected to UV irradiation, and the resulting materials are studied with a variety of analytical techniques including infrared spectroscopy, X-ray absorption near-edge structure spectroscopy, gas chromatography coupled with mass spectrometry, and high-resolution mass spectroscopy. Despite the simplicity of the reactants, these experiments result in the production of a highly complex mixture of molecules from relatively low-mass volatiles (tens of daltons) to high-mass refractory materials (hundreds of daltons). These products include various carboxylic acids, nitriles, and urea, which are also expected to be present on the surface of outer solar system bodies, including Pluto and other transneptunian objects. If these compounds occur in sufficient concentrations in the ices of outer solar system bodies, their characteristic bands may be detectable in the near-infrared spectra of these objects.

  8. A test of genotypic variation in specificity of herbivore-induced responses in Solidago altissima L. (Asteraceae)

    NARCIS (Netherlands)

    Uesugi, A.; Poelman, E.H.; Kessler, A.

    2013-01-01

    Plant-induced responses to multiple herbivores can mediate ecological interactions among herbivore species, thereby influencing herbivore community composition in nature. Several studies have indicated high specificity of induced responses to different herbivore species. In addition, there may be

  9. A novel mechanism for grazing lawn formation: large herbivore-induced modification of the plant-soil water balance

    NARCIS (Netherlands)

    Veldhuis, Michiel; Howison, Ruth; Fokkema, Rienk; Tielens, Elske; Olff, Han

    2014-01-01

    1. Large herbivores play a key role in creating spatial heterogeneity through the formation of grazing lawns. Recent research suggests that the currently accepted nutrient-based theory on the formation of these grazing lawns cannot universally explain their formation in all ecosystems where they are

  10. ß-Glucosidase: an elicitor of herbivore-induced plant odor that attracts host-searching parasitic wasps.

    NARCIS (Netherlands)

    Mattiacci, L.; Dicke, M.; Posthumus, M.A.

    1995-01-01

    Cabbage plants respond to caterpillar (Pieris brassicae) herbivory by releasing a mixture of volatiles that makes them highly attractive to parasitic wasps (Cotesia glomerata) that attack the herbivores. Cabbage leaves that are artificially damaged and subsequently treated with gut regurgitant of P.

  11. The effects of herbivore-induced plant volatiles on interactions between plants and flower-visiting insects

    NARCIS (Netherlands)

    Lucas Gomes Marques Barbosa, D.; Loon, van J.J.A.; Dicke, M.

    2011-01-01

    Plants are faced with a trade-off between on the one hand growth, development and reproduction and on the other hand defence against environmental stresses. Yet, research on insect–plant interactions has addressed plant–pollinator interactions and plant–attacker interactions separately. Plants have

  12. Reduced stomatal conductance in plants grown under elevated carbon dioxide leads to lower emission of herbivore induced volatiles.

    Science.gov (United States)

    Terpene volatiles produced by sweet corn (Zea Mays) upon infestation with pests such as Beet armyworm (Spodoptera exigua) function as part of an indirect plant defense mechanism by attracting parasitoid wasps. To investigate the effect of climate change on this indirect defense, we determined the im...

  13. Catalytic Synthesis of Nitriles in Continuous Flow

    DEFF Research Database (Denmark)

    Nordvang, Emily Catherine

    dehydrogenation of ethylamine and post-reaction purging.Chapter 4 outlines the application of RuO2/Al2O3 catalysts to the oxidative dehydrogenation of benzylamine in air, utilizing a new reaction setup. Again, batch and continuous flow reactions are compared and the effects of reaction conditions, ammonia...

  14. Crystal structure of aqua-(nitrato-κO)dioxido{2-[3-(pyridin-2-yl-κN)-1H-1,2,4-triazol-5-yl-κN (4)]phenolato-κO}uranium(VI) aceto-nitrile monosolvate monohydrate.

    Science.gov (United States)

    Vashchenko, Oleksandr; Raspertova, Ilona; Dyakonenko, Viktoriya; Shishkina, Svitlana; Khomenko, Dmytro; Doroschuk, Roman; Lampeka, Rostislav

    2016-02-01

    In the title compound, [U(C13H9N4O)(NO3)O2(H2O)]·CH3CN·H2O, the U(VI) atom is seven-coordinated in a distorted penta-gonal-bipyramidal N2O5 manner by one tridentate triazole ligand, one monodentate nitrate anion and one water mol-ecule in the equatorial plane and by two uran-yl(VI) O atoms in the axial positions. In the crystal, the U(VI) complex mol-ecule is linked to the water and aceto-nitrile solvent mol-ecules through N-H⋯N, O-H⋯O and O-H⋯N hydrogen bonds, forming a sheet structure parallel to the bc plane. The sheets are further linked by an additional O-H⋯O hydrogen bond, forming a three-dimensional network.

  15. Avaliação do processo de cura da borracha nitrílica (NBR pela resina fenólica através do cálculo da constante de cura Evaluation of phenolic resin vulcanization of nitrile rubber (NBR through determination of the cure constant

    Directory of Open Access Journals (Sweden)

    Ana Maria Furtado

    2001-03-01

    Full Text Available O processo de cura envolve reações de múltiplos mecanismos e sua investigação pode ser feita por meio de várias técnicas. Este trabalho apresenta a comparação entre dois métodos que utilizam parâmetros reométricos para o cálculo da constante cinética de cura (k relacionada com a cura da borracha nitrílica com a resina fenólica, tendo o policloropreno e o óxido de zinco como sistema ativador. Foi utilizado o planejamento de experimentos fatorial completo (2³ + ponto central como base para a preparação das formulações e análise dos resultados. Os resultados obtidos identificaram a influência da temperatura, da quantidade de cada um dos componentes das formulações e da adequação dos métodos de avaliação para o processo de cura da borracha nitrílica pela resina fenólica.The cure process involves reactions with multiple mechanisms and its investigation can be followed by using different techniques. This work compares two methods in which rheometric parameters are used to calculate the cure rate constant (k, related to the cure of nitrile rubber with phenolic resin and having polychloroprene and zinc oxide as the activators. A complete factorial (2³ + central point experimental design was used as base to prepare the formulations and to analyse the results. The results obtained identified the influence of the temperature, the amount of each component in the formulation and the suitability of the evaluation methods for the cure process of nitrile rubber with phenolic resin.

  16. Elimination Reactions of (E)-2,4,6-Trinitrobenzaldehyde O-Benzoyloximes Promoted by R{sub 2}NH/R{sub 2}NH{sub 2}{sup +} in 70 mol% MeCN (aq). Effects of the β-Aryl Group and Leaving Group on Nitrile-Forming Transition States

    Energy Technology Data Exchange (ETDEWEB)

    Pyun, Sang Yong [Pukyong National University, Pusan (Korea, Republic of); Paik, Kyu Cheol; Han, Man So [Daejin University, Pocheon (Korea, Republic of); Cho, Bong Rae [Korea University, Seoul (Korea, Republic of)

    2016-06-15

    Elimination reactions of (E)-2,4,6-(NO{sub 2}){sub 3}C{sub 6}H{sub 2}CH=NOC(O)C{sub 6}H{sub 4}X (3) promoted by R{sub 2}NH/R{sub 2}NH{sub 2}{sup +} in 70 mol% MeCN (aq) have been studied. The reactions produced elimination products and exhibited second-order kinetics. The β and |β{sub lg}| values remained nearly the same for all leaving groups and bases. The results can be described by the negligible p{sub xy} interaction coefficient, p{sub xy} = ∂β/∂pK{sub lg} = ∂β{sub lg}/∂pK{sub BH} ≈ 0, which provides a strong support for the (E1cb){sub irr} mechanism. For eliminations from (E)-ArCH=NOC(O)C{sub 6}H{sub 4}X (1, 3) and (E)-2,4,6-(NO{sub 2}){sub 3}C{sub 6}H{sub 2}CH=NOAr' (2, 3), the change of the β-aryl group (Ar) from 2,4-dinitrophenyl (1) to 2,4,6-trinitrophenyl (3) increased the rate by 270-fold without appreciable change in the transition state structure. On the other hand, the leaving group (OAr') variation from benzoate (3) to 4-nitrophenoxy (2) induced a change in reaction mechanism from (E1cb){sub irr} to E2. These results have been attributed to the cyclic transition state for the nitrile-forming eliminations involving the benzoate leaving group.

  17. Efeito de um novo acelerador de vulcanização nas propriedades reométricas de composições de borracha nitrílica com diferentes teores de AN Effect of a new accelerator of vulcanization in the rheometric properties of nitrile rubber compositions with different AN amounts

    Directory of Open Access Journals (Sweden)

    Iara T. D. de Oliveira

    2010-01-01

    Full Text Available O efeito do tipo de acelerador no processo de vulcanização de compostos de borracha nitrílica com dois teores de acrilonitrila foi investigado. Dois aceleradores comerciais, dissulfeto de 2,2'-dibenzotiazol (MBTS e bis (dimetilditiocarbamato de zinco (ZDMC, de grupos químicos diferentes, tiazol e ditiocarbamato, respectivamente, foram selecionados e comparados com o composto bis (4 metilfenilsulfonilditiocarbimato-zincato (II de tetrabutilamônio (ZNIBU. Os resultados mostram que o tipo de acelerador não só afeta as características de cura, como também tem grande influência nas propriedades físicas. Entre os aceleradores estudados, MBTS foi o menos adequado para a formulação utilizada. Surpreendentemente, verificou-se que o ZNIBU mostrou comportamento intermediário, sendo mais eficaz do que o MBTS e menos eficiente que o ZDMC, considerado um ultra-acelerador, em relação ao tempo ótimo de vulcanização.The effect of the type of accelerator on the vulcanization process of nitrile rubber compounds with two acrilonitrile amounts was investigated. Two commercial accelerators benzothiazole (MBTS and zinc dimethyldithiocarbamate (ZDMC, from different chemical groups, thiazole and dithiocarbamate, respectively, were selected and compared with the compound bis (4 methylphenylsulfonyldithiocarbimato-zincate (II of tetrabutylammoniun (ZNIBU. The results show that the type of accelerator not only affects the cure characteristics, but also has great influence on the physical properties. Among the accelerators studied, MBTS was found to be the least adequate for the formulation used as far as rheometric parameters are concerned. Surprisingly, it was found that ZNIBU showed an intermediate behavior, being more efficient than MBTS but not as much as ZDMC, considered an ultra accelerator, as for the optimum cure time.

  18. How Predictable Are the Behavioral Responses of Insects to Herbivore Induced Changes in Plants? Responses of Two Congeneric Thrips to Induced Cotton Plants

    Science.gov (United States)

    Silva, Rehan; Furlong, Michael J.; Wilson, Lewis J.; Walter, Gimme H.

    2013-01-01

    Changes in plants following insect attack are referred to as induced responses. These responses are widely viewed as a form of defence against further insect attack. In the current study we explore whether it is possible to make generalizations about induced plant responses given the unpredictability and variability observed in insect-plant interactions. Experiments were conducted to test for consistency in the responses of two congeneric thrips, Frankliniella schultzei Trybom and Frankliniella occidentalis Pergrande (Thysanoptera: Thripidae) to cotton seedlings (Gossypium hirsutum Linneaus (Malvales: Malvaceae)) damaged by various insect herbivores. In dual-choice experiments that compared intact and damaged cotton seedlings, F. schultzei was attracted to seedlings damaged by Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), Tetranychus urticae (Koch) (Trombidiforms: Tetranychidae), Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae), F. schultzei and F. occidentalis but not to mechanically damaged seedlings. In similar tests, F. occidentalis was attracted to undamaged cotton seedlings when simultaneously exposed to seedlings damaged by H. armigera, T. molitor or F. occidentalis. However, when exposed to F. schultzei or T. urticae damaged plants, F. occidentalis was more attracted towards damaged plants. A quantitative relationship was also apparent, F. schultzei showed increased attraction to damaged seedlings as the density of T. urticae or F. schultzei increased. In contrast, although F. occidentalis demonstrated increased attraction to plants damaged by higher densities of T. urticae, there was a negative relationship between attraction and the density of damaging conspecifics. Both species showed greater attraction to T. urticae damaged seedlings than to seedlings damaged by conspecifics. Results demonstrate that the responses of both species of thrips were context dependent, making generalizations difficult to formulate. PMID:23691075

  19. Exposure of Lima bean leaves to volatiles from herbivore-induced conspecific plants results in emission of carnivore attractants: active or passive process?

    NARCIS (Netherlands)

    Choh, Y.; Shimoda, T.; Ozawa, R.; Dicke, M.; Takabayashi, J.

    2004-01-01

    There is increasing evidence that volatiles emitted by herbivore-damaged plants can cause responses in downwind undamaged neighboring plants, such as the attraction of carnivorous enemies of herbivores. One of the open questions is whether this involves an active (production of volatiles) or passive

  20. Variation of herbivore-induced volatile terpenes among Arabidopsis ecotypes depends on allelic differences and subcellular targeting of two terpene synthases, TPS02 and TPS03.

    Science.gov (United States)

    Huang, Mengsu; Abel, Christian; Sohrabi, Reza; Petri, Jana; Haupt, Ina; Cosimano, John; Gershenzon, Jonathan; Tholl, Dorothea

    2010-07-01

    When attacked by insects, plants release mixtures of volatile compounds that are beneficial for direct or indirect defense. Natural variation of volatile emissions frequently occurs between and within plant species, but knowledge of the underlying molecular mechanisms is limited. We investigated intraspecific differences of volatile emissions induced from rosette leaves of 27 accessions of Arabidopsis (Arabidopsis thaliana) upon treatment with coronalon, a jasmonate mimic eliciting responses similar to those caused by insect feeding. Quantitative variation was found for the emission of the monoterpene (E)-beta-ocimene, the sesquiterpene (E,E)-alpha-farnesene, the irregular homoterpene 4,8,12-trimethyltridecatetra-1,3,7,11-ene, and the benzenoid compound methyl salicylate. Differences in the relative emissions of (E)-beta-ocimene and (E,E)-alpha-farnesene from accession Wassilewskija (Ws), a high-(E)-beta-ocimene emitter, and accession Columbia (Col-0), a trace-(E)-beta-ocimene emitter, were attributed to allelic variation of two closely related, tandem-duplicated terpene synthase genes, TPS02 and TPS03. The Ws genome contains a functional allele of TPS02 but not of TPS03, while the opposite is the case for Col-0. Recombinant proteins of the functional Ws TPS02 and Col-0 TPS03 genes both showed (E)-beta-ocimene and (E,E)-alpha-farnesene synthase activities. However, differential subcellular compartmentalization of the two enzymes in plastids and the cytosol was found to be responsible for the ecotype-specific differences in (E)-beta-ocimene/(E,E)-alpha-farnesene emission. Expression of the functional TPS02 and TPS03 alleles is induced in leaves by elicitor and insect treatment and occurs constitutively in floral tissues. Our studies show that both pseudogenization in the TPS family and subcellular segregation of functional TPS enzymes control the variation and plasticity of induced volatile emissions in wild plant species.

  1. Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites.

    Science.gov (United States)

    Aratchige, N S; Lesna, I; Sabelis, M W

    2004-01-01

    Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract predatory mites (Neoseiulus cucumeris). Since our aim was to demonstrate such odours and not their relevance under soil conditions, the experiments were carried out using a classic Y-tube olfactometer in which the predators moved on a Y-shaped wire in open air. We found that food-deprived female predators can discriminate between odours from infested bulbs and odours from uninfested bulbs or artificially wounded bulbs. No significant difference in attractiveness to predators was found between clean bulbs and bulbs either wounded 30 min or 3 h before the experiment. These results indicate that it may not be simply the wounding of the bulbs, but rather the feeding by rust mites, which causes the bulb to release odours that attract N. cucumeris. Since bulbs are belowground plant structures, the olfactometer results demonstrate the potential for odour-mediated interactions in the soil. However, their importance in the actual soil medium remains to be demonstrated.

  2. Qualitative and Quantitative Differences in Herbivore-Induced Plant Volatile Blends from Tomato Plants Infested by Either Tuta absoluta or Bemisia tabaci.

    Science.gov (United States)

    Silva, Diego B; Weldegergis, Berhane T; Van Loon, Joop J A; Bueno, Vanda H P

    2017-01-01

    Plants release a variety of volatile organic compounds that play multiple roles in the interactions with other plants and animals. Natural enemies of plant-feeding insects use these volatiles as cues to find their prey or host. Here, we report differences between the volatile blends of tomato plants infested with the whitefly Bemisia tabaci or the tomato borer Tuta absoluta. We compared the volatile emission of: (1) clean tomato plants; (2) tomato plants infested with T. absoluta larvae; and (3) tomato plants infested with B. tabaci adults, nymphs, and eggs. A total of 80 volatiles were recorded of which 10 occurred consistently only in the headspace of T. absoluta-infested plants. Many of the compounds detected in the headspace of the two herbivory treatments were emitted at different rates. Plants damaged by T. absoluta emitted at least 10 times higher levels of many compounds compared to plants damaged by B. tabaci and intact plants. The multivariate separation of T. absoluta-infested plants from those infested with B. tabaci was due largely to the chorismate-derived compounds as well as volatile metabolites of C18-fatty acids and branched chain amino acids that had higher emission rates from T. absoluta-infested plants, whereas the cyclic sesquiterpenes α- and β-copaene, valencene, and aristolochene were emitted at significantly higher levels from B. tabaci-infested plants. Our findings imply that feeding by T. absoluta and B. tabaci induced emission of volatile blends that differ quantitatively and qualitatively, providing a chemical basis for the recently documented behavioral discrimination by two generalist predatory mirid species, natural enemies of T. absoluta and B. tabaci employed in biological control.

  3. Qualitative and Quantitative Differences in Herbivore-Induced Plant Volatile Blends from Tomato Plants Infested by Either Tuta absoluta or Bemisia tabaci

    NARCIS (Netherlands)

    Bastos Silva, Diego; Weldegergis, Berhane T.; Loon, van Joop J.A.; Bueno, Vanda H.P.

    2017-01-01

    Plants release a variety of volatile organic compounds that play multiple roles in the interactions with other plants and animals. Natural enemies of plant-feeding insects use these volatiles as cues to find their prey or host. Here, we report differences between the volatile blends of tomato

  4. How predictable are the behavioral responses of insects to herbivore induced changes in plants? Responses of two congeneric thrips to induced cotton plants.

    Directory of Open Access Journals (Sweden)

    Rehan Silva

    Full Text Available Changes in plants following insect attack are referred to as induced responses. These responses are widely viewed as a form of defence against further insect attack. In the current study we explore whether it is possible to make generalizations about induced plant responses given the unpredictability and variability observed in insect-plant interactions. Experiments were conducted to test for consistency in the responses of two congeneric thrips, Frankliniella schultzei Trybom and Frankliniella occidentalis Pergrande (Thysanoptera: Thripidae to cotton seedlings (Gossypium hirsutum Linneaus (Malvales: Malvaceae damaged by various insect herbivores. In dual-choice experiments that compared intact and damaged cotton seedlings, F. schultzei was attracted to seedlings damaged by Helicoverpa armigera (Hübner (Lepidoptera: Noctuidae, Tetranychus urticae (Koch (Trombidiforms: Tetranychidae, Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae, F. schultzei and F. occidentalis but not to mechanically damaged seedlings. In similar tests, F. occidentalis was attracted to undamaged cotton seedlings when simultaneously exposed to seedlings damaged by H. armigera, T. molitor or F. occidentalis. However, when exposed to F. schultzei or T. urticae damaged plants, F. occidentalis was more attracted towards damaged plants. A quantitative relationship was also apparent, F. schultzei showed increased attraction to damaged seedlings as the density of T. urticae or F. schultzei increased. In contrast, although F. occidentalis demonstrated increased attraction to plants damaged by higher densities of T. urticae, there was a negative relationship between attraction and the density of damaging conspecifics. Both species showed greater attraction to T. urticae damaged seedlings than to seedlings damaged by conspecifics. Results demonstrate that the responses of both species of thrips were context dependent, making generalizations difficult to formulate.

  5. The Rice Transcription Factor WRKY53 Suppresses Herbivore-Induced Defenses by Acting as a Negative Feedback Modulator of Mitogen-Activated Protein Kinase Activity1

    Science.gov (United States)

    Hu, Lingfei; Ye, Meng; Zhang, Tongfang; Zhou, Guoxin; Wang, Qi; Lu, Jing

    2015-01-01

    The mechanisms by which herbivore-attacked plants activate their defenses are well studied. By contrast, little is known about the regulatory mechanisms that allow them to control their defensive investment and avoid a defensive overshoot. We characterized a rice (Oryza sativa) WRKY gene, OsWRKY53, whose expression is rapidly induced upon wounding and induced in a delayed fashion upon attack by the striped stem borer (SSB) Chilo suppressalis. The transcript levels of OsWRKY53 are independent of endogenous jasmonic acid but positively regulated by the mitogen-activated protein kinases OsMPK3/OsMPK6. OsWRKY53 physically interacts with OsMPK3/OsMPK6 and suppresses their activity in vitro. By consequence, it modulates the expression of defensive, MPK-regulated WRKYs and thereby reduces jasmonic acid, jasmonoyl-isoleucine, and ethylene induction. This phytohormonal reconfiguration is associated with a reduction in trypsin protease inhibitor activity and improved SSB performance. OsWRKY53 is also shown to be a negative regulator of plant growth. Taken together, these results show that OsWRKY53 functions as a negative feedback modulator of MPK3/MPK6 and thereby acts as an early suppressor of induced defenses. OsWRKY53 therefore enables rice plants to control the magnitude of their defensive investment during early signaling. PMID:26453434

  6. Variation in herbivore-induced plant volatiles corresponds with spatial heterogeneity in the level of parasitoid competition and parasitoid exposure to hyperparasitism

    NARCIS (Netherlands)

    Poelman, E.H.; Harvey, J.A.; van Loon, J.J.A.; Vet, L.E.M.; Dicke, M.

    2013-01-01

    Reproductive success for species in which offspring are confined to a distinct resource depends on the ability of parents to locate reproductive sites as well as the quality of these sites in terms of the food source, risk of predation and competition. To locate hosts for their offspring, parasitic

  7. Variation of Herbivore-Induced Volatile Terpenes among Arabidopsis Ecotypes Depends on Allelic Differences and Subcellular Targeting of Two Terpene Synthases, TPS02 and TPS031[W][OA

    Science.gov (United States)

    Huang, Mengsu; Abel, Christian; Sohrabi, Reza; Petri, Jana; Haupt, Ina; Cosimano, John; Gershenzon, Jonathan; Tholl, Dorothea

    2010-01-01

    When attacked by insects, plants release mixtures of volatile compounds that are beneficial for direct or indirect defense. Natural variation of volatile emissions frequently occurs between and within plant species, but knowledge of the underlying molecular mechanisms is limited. We investigated intraspecific differences of volatile emissions induced from rosette leaves of 27 accessions of Arabidopsis (Arabidopsis thaliana) upon treatment with coronalon, a jasmonate mimic eliciting responses similar to those caused by insect feeding. Quantitative variation was found for the emission of the monoterpene (E)-β-ocimene, the sesquiterpene (E,E)-α-farnesene, the irregular homoterpene 4,8,12-trimethyltridecatetra-1,3,7,11-ene, and the benzenoid compound methyl salicylate. Differences in the relative emissions of (E)-β-ocimene and (E,E)-α-farnesene from accession Wassilewskija (Ws), a high-(E)-β-ocimene emitter, and accession Columbia (Col-0), a trace-(E)-β-ocimene emitter, were attributed to allelic variation of two closely related, tandem-duplicated terpene synthase genes, TPS02 and TPS03. The Ws genome contains a functional allele of TPS02 but not of TPS03, while the opposite is the case for Col-0. Recombinant proteins of the functional Ws TPS02 and Col-0 TPS03 genes both showed (E)-β-ocimene and (E,E)-α-farnesene synthase activities. However, differential subcellular compartmentalization of the two enzymes in plastids and the cytosol was found to be responsible for the ecotype-specific differences in (E)-β-ocimene/(E,E)-α-farnesene emission. Expression of the functional TPS02 and TPS03 alleles is induced in leaves by elicitor and insect treatment and occurs constitutively in floral tissues. Our studies show that both pseudogenization in the TPS family and subcellular segregation of functional TPS enzymes control the variation and plasticity of induced volatile emissions in wild plant species. PMID:20463089

  8. A new one-pot synthesis of 1, 2, 4-oxadiazoles from aryl nitriles ...

    Indian Academy of Sciences (India)

    Young Researchers and Elites Club, North Tehran Branch, Islamic Azad University, Tehran 15742, Iran; Department of Chemistry, School of Sciences, Alzahra University, 1993891176, Vanak, Tehran, Iran; Institute of Hydrogen Economy, Energy Research Alliance, International Campus, Universiti Teknologi Malaysia, ...

  9. A new one-pot synthesis of 1,2,4-oxadiazoles from aryl nitriles ...

    Indian Academy of Sciences (India)

    by esterification in tetrahydrofuran (THF) and cycliza- tion/dehydration in dimethyl sulphoxide (DMSO) to give 1,2,4-oxadiazole (scheme 1). In general, there is no need to remove THF after esterification and both cyclizations/dehydrations are facilitated in high tempe- ratures by addition of DMSO, and therefore these three.

  10. Observations of Nitrogen Fractionation in Prestellar Cores: Nitriles Tracing Interstellar Chemistry

    Science.gov (United States)

    Milam, S. N.; Charnley, S. B.

    2012-01-01

    Primitive materials provide important clues on the processes that occurred during the formation and early evolution of the Solar System. Space-based and ground-based observations of cometary comae show that comets appear to contain a mixture of the products of both interstellar and nebular chemistries. Significant 15-nitrogen enrichments have been measured in CN and HCN towards a number of comets and may suggest an origin of interstellar chemical fractionation. Additionally, large N-15 enhancements are found in meteorites and has also led to to the view that the N-15 traces material formed in the interstellar medium (ISM), although multiple sources cannot be excluded. Here, we show the results of observations of the nitrogen and carbon fractionation in prestellar cores for various N-bearing species to decipher the origin of primitive material isotopic enrichments.

  11. Permeation of Military Fuels Through Nitrile-Coated Fabrics Used for Collapsible Fuel Storage Containers

    Science.gov (United States)

    2014-03-01

    Technology 1999, 322. 7. Spence, K.; Venditti; R.; Rojas, O.et al. Water Vapor Barrier Properties of Coated and Filled Microfibrillated Cellulose...Composite Films, Bioresources 2011, 6 (4), 4370. 14 INTENTIONALLY LEFT BLANK. 15 List of Symbols, Abbreviations, and Acronyms ASTM American

  12. Could nitrile derivatives of turnip (Brassica rapa) glucosinolates be Hepato-and/or cholangiotoxic in cattle?

    Science.gov (United States)

    Turnip (Brassica rapa ssp. rapa) and rape (Brassica napus ssp. biennis) and other brassica forage crops are generally regarded as “safe” feed for cattle during late summer and fall in New Zealand. However, when Pithomyces chartarum spore counts are high there are epidemics of sporidesmin toxicity (...

  13. Synthetic transformations of a pendant nitrile moiety in group 4 metallocene complexes

    Czech Academy of Sciences Publication Activity Database

    Pinkas, Jiří; Císařová, I.; Kubišta, Jiří; Horáček, Michal; Lamač, Martin

    2013-01-01

    Roč. 42, č. 19 (2013), s. 7101-7110 ISSN 1477-9226 R&D Projects: GA ČR GPP207/10/P200 Institutional support: RVO:61388955 Keywords : structural characterization * chemistry * functional titanocenes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.097, year: 2013

  14. Infrared Spectra, Index of Refraction, and Optical Constants of Nitrile Ices Relevant to Titan's Atmosphere

    Science.gov (United States)

    Moore, Marla; Ferrante, Robert; Moore, William; Hudson, Reggie

    2010-01-01

    Spectra and optical constants of nitrite ices known or suspected to be in Titan's atmosphere are presented from 2.5 to 200 microns (4000 to 50 per cm ). These results are relevant to the ongoing modeling of Cassini CIRS observations of Titan's winter pole. Ices studied include: HCN, hydrogen cyanide; C2N2, cyanogen; CH3CN, acetonitrile; C 2H5CN, propionitrile; and HC3N, cyanoacetylene. For each of these molecules we report new measurements of the index of refraction, n, determined in both the amorphous- and crystallinephase at 670 nm. Spectra were measured and optical constants were calculated for each nitrite at a variety of temperatures including 20, 35, 50, 75, 95, and 110 K, in the amorphous- and crystalline-phase. This laboratory effort uses a dedicated FTIR spectrometer to record transmission spectra of thin-film ice samples. Laser interference is used to measure film thickness during condensation onto a transparent cold window attached to the tail section of a closed-cycle helium cryostat. Optical constants, real (n) and imaginary (k) refractive indices, are determined using Kramers-Kronig (K-K) analysis. Our calculation reproduces the complete spectrum, including all interference effects. Index of refraction measurements are made in a separate dedicated FTIR spectrometer where interference deposit fringes are measured using two 670 nm lasers at different angles to the ice substrate. A survey of these new measurements will be presented along with a discussion of their validation, errors, and application to Titan data.

  15. Qualitative and quantitative variation among volatile profiles induced by Tetranychus urticae feeding on plants from various families.

    Science.gov (United States)

    van den Boom, Cindy E M; van Beek, Teris A; Posthumus, Maarten A; de Groot, Aede; Dicke, Marcel

    2004-01-01

    Many plant species are known to emit herbivore-induced volatiles in response to herbivory. The spider mite Tetranychus urticae Koch is a generalist that can feed on several hundreds of host plant species. Volatiles emitted by T. urticae-infested plants of 11 species were compared: soybean (Glycine max), golden chain (Laburnum anagyroides), black locust (Robinia pseudo-acacia), cowpea (Vigna unguiculata), tobacco (Nicotiana tabacum), eggplant (Solanum melalonga), thorn apple (Datura stramonium), sweet pepper (Capsicum annuum), hop (Humulus lupulus), grapevine (Vitis vinifera), and ginkgo (Ginkgo biloba). The degree to which the plant species produced novel compounds was analyzed when compared to the odors of mechanically damaged leaves. Almost all of the investigated plant species produced novel compounds that dominated the volatile blend, such as methyl salicylate, terpenes, oximes, and nitriles. Only spider mite-infested eggplant and tobacco emitted a blend that was merely quantitatively different from the blend emitted by mechanically damaged or clean leaves. We hypothesized that plant species with a low degree of direct defense would produce more novel compounds. However, although plant species with a low direct defense level do use indirect defense to defend themselves, they do not always emit novel compounds. Plant species with a high level of direct defense seem to invest in the production of novel compounds. When plant species of the Fabaceae were compared to plant species of the Solanaceae, qualitative differences in spider mite-induced volatile blends seemed to be more prominent in the Fabaceae than in the Solanaceae.

  16. Volatiles emitted from tea plants infested by Ectropis obliqua larvae are attractive to conspecific moths.

    Science.gov (United States)

    Sun, Xiao-Ling; Wang, Guo-Chang; Gao, Yu; Zhang, Xin-Zhong; Xin, Zhao-Jun; Chen, Zong-Mao

    2014-10-01

    Herbivore-induced plant volatiles have been reported to play a role in the host-searching behavior of herbivores. However, next to nothing is known about the effect of volatiles emitted from tea plants infested by Ectropis obliqua larvae on the behavior of conspecific adults. Here, we found that tea plants infested by E. obliqua caterpillars for 24 h were more attractive to both virgin male and female E. obliqua adults than were intact, uninfested tea plants; moreover, mated female E. obliqua moths were more attracted by infested tea plants and preferentially oviposited on these plants, whereas male moths were repelled by infested plants once they had mated. Volatile analysis revealed that the herbivore infestation dramatically increased the emission of volatiles. Among these volatiles, 17 compounds elicited antennal responses from both male and female virginal moths. Using a Y-tube olfactometer, we found that 3 of the 17 chemicals, benzyl alcohol, (Z)-3-hexenyl hexanoate, and (Z)-3-hexenal, were attractive, but two compounds, linalool and benzyl nitril, were repellent to virgin male and female moths. One chemical, (Z)-3-hexenyl acetate, was attractive only to virgin males. Mated females were attracted by three compounds, (Z)-3-hexenyl hexanoate, (Z)-3-hexenyl acetate, and (Z)-3-hexenal; whereas mated males were repelled by (Z)-3-hexenol. The findings provide new insights into the interaction between tea plants and the herbivores, and may help scientists develop new measures with which to control E. obliqua.

  17. The Effect of Novolac and Graphite Polycrystal on the Acetone Penetration and Thermal Resistance of Nanocomposites Based on Nitrile Rubber

    Directory of Open Access Journals (Sweden)

    Rasool Mahboudi

    2015-03-01

    Full Text Available Developments of high diffusive environments in coincidence with emerging fluids with strong ability to destroy polymeric systems have resulted in rapid deformation and destruction of polymeric parts when in contact with such aggressive environments. Therefore, nowadays, there is a great need to develop highly resistant materials towards aggressive chemicals and harsh conditions. In this paper the effect of graphite polycrystal powders and novolac type phenolic resin has been experimentally studied towards acetone diffusion and thermal stability of polyacrylonitrile butadiene rubber/novolac/graphite polycrystal nanocomposites. The results obtained from dynamic mechanical thermal analysis (DMTA and swelling in acetone showed that after 32 h samples reached to 94.2% of final swelling state. By using Avrami equation and swelling experimental data, the functionality of Ln(m/m0 to novolac and graphite polycrystal weight fraction and test duration time were evaluated. This theoretical equation evaluated and predicted the amount of Ln(m/m0 with 5.92% error after 32 h. Increases in graphite polycrystal content were followed by decreases in diffusion of acetone and modulus, before glass transition temperature, and increased thermal stability and thermal resistance of the nanocomposites. Increases in novolac content by 35 wt%, decreased glass transition temperature, thermal stability and thermal resistance of the nanocomposites. In nanocomposite, containing 45 wt% of novolac, dynamic mechanical thermal analysis (DMTA data and scanning electron microscope (SEM images showed phase separation of thermoset and elastomer in the nanocomposite blend.

  18. Comets as Messengers from the Early Solar System - Emerging Insights on Delivery of Water, Nitriles, and Organics to Earth

    Science.gov (United States)

    Mumma, Michael J.; Charnley, Steven B.

    2012-01-01

    The question of exogenous delivery of water and organics to Earth and other young planets is of critical importance for understanding the origin of Earth's volatiles, and for assessing the possible existence of exo-planets similar to Earth. Viewed from a cosmic perspective, Earth is a dry planet, yet its oceans are enriched in deuterium by a large factor relative to nebular hydrogen and analogous isotopic enrichments in atmospheric nitrogen and noble gases are also seen. Why is this so? What are the implications for Mars? For icy Worlds in our Planetary System? For the existence of Earth-like exoplanets? An exogenous (vs. outgassed) origin for Earth's atmosphere is implied, and intense debate on the relative contributions of comets and asteroids continues - renewed by fresh models for dynamical transport in the protoplanetary disk, by revelations on the nature and diversity of volatile and rocky material within comets, and by the discovery of ocean-like water in a comet from the Kuiper Belt (cf., Mumma & Charnley 2011). Assessing the creation of conditions favorable to the emergence and sustenance of life depends critically on knowledge of the nature of the impacting bodies. Active comets have long been grouped according to their orbital properties, and this has proven useful for identifying the reservoir from which a given comet emerged (OC, KB) (Levison 1996). However, it is now clear that icy bodies were scattered into each reservoir from a range of nebular distances, and the comet populations in today's reservoirs thus share origins that are (in part) common. Comets from the Oort Cloud and Kuiper Disk reservoirs should have diverse composition, resulting from strong gradients in temperature and chemistry in the proto-planetary disk, coupled with dynamical models of early radial transport and mixing with later dispersion of the final cometary nuclei into the long-term storage reservoirs. The inclusion of material from the natal interstellar cloud is probable, for comets formed in the outer solar system.

  19. Formation of simple nitriles upon glucosinolate hydrolysis affects direct and indirect defense against the specialist herbivore, Pieris rapae

    NARCIS (Netherlands)

    Mumm, R.; Burow, M.; Bukovinszkine-Kiss, G.; Kazantzidou, E.; Wittstock, U.; Dicke, M.; Gershenzon, J.

    2008-01-01

    The glucosinolate-myrosinase system, found in plants of the order Brassicales, has long been considered an effective defense system against herbivores. The defensive potential of glucosinolates is mainly due to the products formed after myrosinase-catalyzed hydrolysis upon tissue damage. The most

  20. A qualitative approach for predicting the Microtox (Photobacterium phosphoreum) toxicity of nitriles and nitro compounds using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, K.L.E.; McKinnon, M.B.; Niculescu, S.P. [National Water Research Inst., Burlington, Ontario (Canada)

    1995-12-31

    The recent availability of a large normalized toxicity database (COMPUTOX{trademark}) and modern neural network algorithms, allows the possibility to develop representative QSAR models over large toxicity ranges. Exploration of organic cyanides using a feed-forward backpropagation neural network model produces interesting results. This non-congeneric data set (N = 73), covering over 6 orders of magnitude, was used to predict Microtox toxicity via 31 functional group descriptors, an exploded chemical formula and log P. The training data for the network was obtained in two steps: first, statistical standardizing of each of the 51 data input fields and second, transformation/compression using the sigmoid logistic function. The feedforward neural model, architecture 51-26-13-1, provided the best feedback to the training using the criteria of accuracy and presence of the white noise Gaussian character of the residuals (for computing confidence intervals). The model was validated with a simplified Jacknife procedure by randomly splitting the data into five disjoint subsets of (almost) equal volume. For each of the subsets, the weights obtained from training the network on the complementary data subsets after 1,000, 1,500, 2,000, 2,500 and 3,000 training cycles, were computed and, with input from the considered subset, used to predict Microtox values. Finally, the sets consisting of measured and predicted values were reassembled. The best correlation, between measured and predicted values was obtained at 1,500 training cycles. Simultaneously, the distribution of the residuals showed pronounced white noise Gaussian character. Higher numbers of cycles cause overtraining, due to memorization of the input data. The results prove the predictive capacity of this neural network model and show that it is appropriate for this data set. Similar results were obtained for other chemical classes.

  1. Whole glove permeation of cyclohexanol through disposable nitrile gloves on a dextrous robot hand: Fist clenching vs. non-clenching.

    Science.gov (United States)

    Mathews, Airek R; Que Hee, Shane S

    2017-04-01

    The differences in permeation parameters when a gloved dextrous robot hand clenched and did not were investigated with the dynamic permeation system described in the companion paper. Increased permeation through the gloves of the present study for cyclohexanol when the gloved hand clenched depended on glove thickness and porosity for cyclohexanol permeation. The Sterling glove, the thinnest and most porous, was the least protective. Hand clenching promoted more permeation for the Sterling glove in terms of breakthrough times, steady state permeation rate, and diffusion coefficient. The Safeskin glove showed increased permeation only for the steady state permeation rate but not breakthrough times or diffusion coefficient. The Blue and Purple gloves showed no differences when the hand was clenching or not. The correlational analysis supported differences between the clenching and non-clenching situations, and the risk assessment considered the worst and best scenarios relative to one and two hydrated hands that were and were not protected by specific gloves.

  2. Quantification of free plus conjugated indoleacetic acid in arabidopsis requires correction for the nonenzymatic conversion of indolic nitriles.

    Science.gov (United States)

    Llić, N; Normanly, J; Cohen, J D

    1996-07-01

    The genetic advantages to the use of Arabidopsis thaliana mutants for the study of auxin metabolism previously have been partially offset by the complexity of indolic metabolism in this plant and by the lack of proper methods. To address some of these problems, we developed isotopic labeling methods to determine amounts and examine the metabolism of indolic compounds in Arabidopsis. Isolation and indentification of endogenous indole-3-acetonitrile (IAN; a possible precursor of the auxin indole-3-acetic acid [IAA]) was carried out under mild conditions, thus proving its natural occurrence. We describe here the synthesis of 13C1-labeled IAN and its utility in the gas chromatography-mass spectrometry quantification of endogenous IAN levels. We also quantified the nonenzymatic conversion of IAN to IAA under conditions used to hydrolyze IAA conjugates. 13C1-Labeled IAN was used to assess the contribution of IAN to measured IAA following hydrolysis of IAA conjugates. We studied the stability and breakdown of the indolic glucosinolate glucobrassicin, which is known to be present in Arabidopsis. This is potentially an important concern when using Arabidopsis for studies of indolic biochemistry, since the levels of indolic auxins and auxin precursors are well below the levels of the indolic glucosinolates. We found that under conditions of extraction and base hydrolysis, formation of IAA from glucobrassicin was negligible.

  3. Nitrilase from rhodococcus rhodochrous ATCC BAA-870: fibre formation over time

    CSIR Research Space (South Africa)

    Frederick, J

    2008-07-01

    Full Text Available possesses nitrile-hydrolysing enzymes capable of metabolising a wide range of aliphatic and aromatic nitriles and amides. The biocatalyst expressed a two enzyme system with sequential nitrile-converting activity. Nitrilase enzymes catalyse the hydrolysis...

  4. Slow-cycle effects of foliar herbivory alter the nitrogen acquisition and population size of Collembola

    Science.gov (United States)

    Mark A. Bradford; Tara Gancos; Christopher J. Frost

    2008-01-01

    In terrestrial systems there is a close relationship between litter quality and the activity and abundance of decomposers. Therefore, the potential exists for aboveground, herbivore-induced changes in foliar chemistry to affect soil decomposer fauna. These herbivore-induced changes in chemistry may persist across growing seasons. While the impacts of such slow-cycle...

  5. Integrating Studies on Plant-Pollinator and Plant-Herbivore Interactions

    NARCIS (Netherlands)

    Lucas-Barbosa, Dani

    2016-01-01

    Research on herbivore-induced plant defence and research on pollination ecology have had a long history of separation. Plant reproduction of most angiosperm species is mediated by pollinators, and the effects of herbivore-induced plant defences on pollinator behaviour have been largely neglected.

  6. Isolation and characterization of Rhodococcus ruber CGMCC3090 ...

    African Journals Online (AJOL)

    A bacterial strain was isolated from soil samples that had been polluted by nitrile compounds. This strain converts acrylonitrile to acrylamide with high activity. The nitrile hydrolysis activity was tested using eight substrates, including aliphatic, aromatic and heterocyclic (di)nitriles. All of the nitrile compounds were hydrolyzed ...

  7. Isolation and characterization of Rhodococcus ruber CGMCC3090 ...

    African Journals Online (AJOL)

    This strain converts acrylonitrile to acrylamide with high activity. The nitrile hydrolysis activity was tested using eight substrates, including aliphatic, aromatic and heterocyclic (di)nitriles. All of the nitrile compounds were hydrolyzed by the resting cells. The main (cyano-)amide products demonstrated that nitrile hydratase was ...

  8. Sifat fisika dan analisis gugus fungsi karet seal o-ring dari bahan termoplastik elastomer nitrile butadiene rubber (NBR) dan polyvinyl chloride (PVC)

    OpenAIRE

    Arum Yuniari; Nursamsi Sarengat

    2013-01-01

    The purpose of this research was to determine the physical properties and functional groups on O-ring rubber seals made of thermoplastic elastomers blend NBR and PVC. Composition of the NBR / PVC were successively varied : 90/10; 85/15; 80/20; 75/25; 70/30 and 65/35 phr. Mixing process between NBR/PVC with additive used a two roll mill within a temperature of 60º - 80 ºC, the vulcanization process used a hydraulic press at a temperature of 170 oC and pressure of 150 kg/cm2. The...

  9. Sifat Fisika Dan Analisis Gugus Fungsi Karet Seal O-ring Dari Bahan Termoplastik Elastomer Nitrile Butadiene Rubber (NBR) Dan Polyvinyl Chloride (PVC)

    OpenAIRE

    Yuniari, Arum; Sarengat, Nursamsi

    2013-01-01

    The purpose of this research was to determine the physical properties and functionalgroups on O-ring rubber seals made of thermoplastic elastomers blend NBR and PVC.Composition of the NBR / PVC were successively varied : 90/10; 85/15; 80/20; 75/25; 70/30 and65/35 phr. Mixing process between NBR/PVC with additive used a two roll mill within atemperature of 60º - 80 ºC, the vulcanization process used a hydraulic press at a temperature of170 oC and pressure of 150 kg/cm2. The physical properties...

  10. New dual-phase polymer electrolytes prepared from NBR/SBR lattices. [polyacryloNitrile-Butadiene Rubber/poly(Styrene-Butadiene) copolymer Rubber

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Morihiko; Ichino, Toshihiro; Rutt, J.S.; Nishi, Shiro (Nippon Telegraph and Telephone Corp., Tokyo (Japan). NTT Interdisciplinary Research Lab.)

    1993-10-01

    A new type of Li[sup +] ion conducting polymer electrolytes consisting of two phases, one of which is a highly polar region (impregnated with lithium salt solution), forming ion-conductive channels, while the other is a nonpolar region, forming supporting polymer matrices have been prepared from NBR/SBR lattices. TEM measurement and EDX analysis show evidence that dual-phase structure is constructed in the electrolyte. Ionic conductivity of the electrolyte increases with increase of lithium salt solution content. Maximum ionic conductivity of 2.2 [times] 10[sup [minus]3] S/cm is obtained at the lithium salt solution content of 60.5% (w/w). The electrolyte retains rubber-like film with good mechanical strength despite the presence of the solution.

  11. Synthetic Applications of the Parkins Nitrile Hydration Catalyst [PtH{(PMe2O2H}(PMe2OH]: A Review

    Directory of Open Access Journals (Sweden)

    Victorio Cadierno

    2015-08-01

    Full Text Available The air-stable hydride-platinum(II complex [PtH{(PMe2O2H}(PMe2OH], reported by Parkins and co-workers in 1995, is the most versatile catalyst currently available for the hydration of C≡N bonds. It features remarkable activity under relatively mild conditions and exceptionally high functional group compatibility, facts that have allowed the implementation of this complex in the synthesis of a large number of structurally complex, biologically active molecules and natural products. In this contribution, synthetic applications of the Parkins catalyst are reviewed.

  12. Tandem Blaise/Palladium-Catalyzed Ullmann Coupling for the One-Pot Synthesis of Enamino Ester-Functionalized Biaryls from Nitriles.

    Science.gov (United States)

    Xuan, Zi; Kim, Ju Hyun; Lee, Sang-gi

    2015-08-07

    A novel Pd-catalyzed Ullmann-type homocoupling reaction of the Blaise reaction intermediate generated by the reaction of 2-bromo arylnitriles and a Reformatsky reagent has been developed for one-pot synthesis of enamino ester-functionalized biaryls 2 in good yields. The 2,2'-substituted enamine moieties of the coupling products could be cyclized under acidic conditions through the conjugate addition/deamination cascade to afford the seven-membered N-heterocyclics 3 with biaryl backbone in excellent yields.

  13. Synthetic Applications of the Parkins Nitrile Hydration Catalyst [PtH{(PMe2O)2H}(PMe2OH)]: A Review

    National Research Council Canada - National Science Library

    Victorio Cadierno

    2015-01-01

    The air-stable hydride-platinum(II) complex [PtH{(PMe2O)2H}(PMe2OH)], reported by Parkins and co-workers in 1995, is the most versatile catalyst currently available for the hydration of C≡N bonds...

  14. X, Ku-band microwave-absorption properties of polyarylene ether nitriles terminated with phthalonitrile/Fe{sub 3}O{sub 4} hybrid submicron spheres

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Lifen, E-mail: 361626614@qq.com; Pu, Zejun; Huang, Xu; Liu, Xiaobo, E-mail: liuxb@uestc.edu.cn

    2014-05-01

    Highlights: • PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid spheres were prepared via one-step solvothermal method. • Polymer compatibility is introduced into inorganic submicron spheres successfully. • PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres possessed good ferrimagnetism. • Control the microwave absorption band of PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres. - Abstract: A novel series of PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres with different additions of PEN-t-Ph have been prepared successfully via solvothermal method, and their structures and morphologies were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometer (EDS), Fourier transform infrared spectrophotometer (FTIR), and scanning electron microscopy (SEM). The results revealed that the crystallinity, dispersity, and size of hybrid submicron spheres can be controlled by altering the addition content of PEN-t-Ph. Magnetization measurement showed that the PEN-t-Ph/Fe{sub 3}O{sub 4} hybrid submicron spheres possessed good ferrimagnetism. The electromagnetic measurement indicated that the resonance peaks of complex permittivity, complex permeability, dielectric loss, and magnetic loss were shifted to the higher frequency as the addition of PEN-t-Ph increased. Moreover, the microwave absorption band was also shifted to higher frequency as the addition of PEN-t-Ph increased. Through this method, the polymer compatibility can be introduced into inorganic submicron spheres, which could provide the inorganic particles with more applications.

  15. Sifat fisika dan analisis gugus fungsi karet seal o-ring dari bahan termoplastik elastomer nitrile butadiene rubber (NBR dan polyvinyl chloride (PVC

    Directory of Open Access Journals (Sweden)

    Arum Yuniari

    2013-06-01

    Full Text Available The purpose of this research was to determine the physical properties and functional groups on O-ring rubber seals made of thermoplastic elastomers blend NBR and PVC. Composition of the NBR / PVC were successively varied : 90/10; 85/15; 80/20; 75/25; 70/30 and 65/35 phr. Mixing process between NBR/PVC with additive used a two roll mill within a temperature of 60º - 80 ºC, the vulcanization process used a hydraulic press at a temperature of 170 oC and pressure of 150 kg/cm2. The physical properties were evaluated including tensile strength, elongation at break, hardness, before and after aging, hardness after immersion in isooctane and swelling while analysis of functional groups was also carried out by method of Fourier Transform Infrared Spectrophotometer (FTIR. The result of the best vulcanized was characterized by tensile strength 188.93 kg/cm2, the change of tensile strength after aging 2.50%, elongation at break of 400%, the change of elongation at break after aging was 12.5%, hardness 75 shore A, the change of hardness after aging 0%, the change of hardness after immersion in isooctane 1.3%, swelling 0.8% and functional group of vulcanisate was indicated by new peak (OH at wave band of 3468 cm-1. Those formula met the requirements of the technical specifications of ASTM D 2000 seal O-ring.

  16. Aza Diels-Alder Reactions of Nitriles, N,N-Dimethylhydrazones, and Oximino Ethers. Application in Formal [2 + 2 + 2] Cycloadditions for the Synthesis of Pyridines.

    Science.gov (United States)

    Hamzik, Philip J; Goutierre, Anne-Sophie; Sakai, Takeo; Danheiser, Rick L

    2017-12-15

    Metal-free, formal [2 + 2 + 2] cycloaddition strategies for the synthesis of polycyclic pyridine derivatives are described. The overall transformation proceeds via a two-stage pericyclic cascade mechanism. In the first step, an intramolecular propargylic ene reaction generates a vinylallene that is necessarily locked in the s-cis conformation. This vinylallene exhibits exceptional reactivity as a Diels-Alder reaction partner and engages in [4 + 2] cycloadditions with normally unreactive azadienophiles including unactivated cyano groups and heterosubstituted imine derivatives such as dimethylhydrazones and oximino ethers. Few examples of oximino ether Diels-Alder reactions have been reported previously, and normal electron-demand [4 + 2] cycloadditions of unactivated dialkylhydrazones are unprecedented. Overall, this metal-free formal [2 + 2 + 2] cycloaddition provides access to polycyclic pyridine derivatives and complements transition-metal-catalyzed [2 + 2 + 2] strategies.

  17. Graft copolymerization of acrylo–nitrile onto delignified native bamboo (Bambusa vulgaris cellulosic and its utilization potential for heavy metal uptake from aqueous medium

    Directory of Open Access Journals (Sweden)

    M.O. EKEBAFE

    2011-06-01

    Full Text Available Graft polymerization of acrylonitrile onto delingnified cellulosic material obtained from Nigeria grown bamboo (Bambusa vulgaris could be initiated by a ceric ammonium nitrate redox system. Optimization of grafting of acrylonitrile onto cellulosic material was performed by varying the reaction conditions, such as the duration of soaking of cellulosic material in ceric ammonium nitrate solution, concentration of ceric ammonium nitrate solution, polymerization time, temperature of reaction, and acrylonitrile concentration and saponification time, in order to study their influence on percent grafting yield and grafting efficiency. The resulting cellulosic-g-polyacrylonitrile (PAN copolymers were fractionated by extraction at 33 C with N,N’-dimethylformamide. Fractions were characterized by determining both the % add-on and the free polymer. Saponification of grafted copolymer was done by reaction with sodium hydroxide followed by methanol precipitation. The absorbent polymer so produced gave fair water retention values. The optimum reaction conditions obtained were: 20 mmol/L ceric ammonium nitrate solution in 1% nitric acid, soaking duration of 0.5 h at 40 C for a polymerization time of 2 h and saponification time of 3 h. The percent grafting was 167.89%, grafting efficiency was 93.52% and water retention value was 389 g/g. The grafting was confirmed using FTIR. Sorption of different metal ions in the mixture, e.g. Cr, Mn, Ni, Cu and Pb, by grafted cellulosic and the hydrogel was also investigated. Hydrolysis increases the sorption affinity of grafted cellulose toward water and metal ions.

  18. Nitril Grubu Tasıyan Kaliks[4]aren ve Polimer Destekli Türevinin Sentezi ve Civa Taşıma Özelliklerinin Karşılaştırılması

    Directory of Open Access Journals (Sweden)

    Gülderen UYSAL AKKUŞ

    2009-04-01

    Full Text Available Bu çalışma 5,11,17,23-tetra-ter-bütil-25,27-bis(3siyanopropoksikaliks[4]aren (2 ve bunun birden fazla kaliksaren birimininin bir arada olduğu uygun polimerik yapısının sentezini ve ekstraksiyon özelliklerini içermektedir. Başlangıç maddesi olarak kullanılan p-ter-bütilkaliks[4]aren literatürdeki metotlara göre sentezlendi. Daha sonra bu bileşiğe literatürdeki metotlar uyarlanarak 2 nolu bileşik elde edildi. Polimerik yapı (3 bileşik 2 ile Merrifield reçinesinin reaksiyonuyla elde edildi. Son olarak bu bileşiklerin faz-transfer çalışmaları sıvı-sıvı ekstraksiyon metodu kullanılarak gerçekleştirildi. Ekstraksiyon sonuçlarından görülmektedir ki monomer 2 Hg+2 katyonuna karşı bir seçicilik göstermektedir. Halbuki, bunun polimeri (3 Ni2+ hariç seçilen metallerin hepsini iyi bir şekilde organik faza taşımaktadır.

  19. 1,3-Dipolar cycloadditions of ethoxycarbonyl-nitrile benzylimine and synthesis of ß-amino acids. Synthesis and reactions of ethyl 2-chloro-2-ethoxyacetate and 2-chloro-2-ethoxyacetylchloride

    DEFF Research Database (Denmark)

    Bach, K.K.; El-Seedi, H.R.; Jensen, H.M.

    1994-01-01

    -amines and subsequent hydrolysis gave beta-amino acids. The syntheses of the title reagents were described. Ethyl 2-chloro-2-ethoxy-acetate gave selectively oximes, hydrazones, nitrones, and phosphonium salts with hydroxylamine, hydrazines, N-substituted hydroxylamines and triphenylphosphine respectively...

  20. Terpenoid biosynthesis in Arabidopsis attacked by caterpillars and aphids

    NARCIS (Netherlands)

    Kroes, Anneke; Weldegergis, Berhane T.; Cappai, Francesco; Dicke, Marcel; Loon, van Joop J.A.

    2017-01-01

    One of the responses of plants to insect attack is the production of volatile organic compounds that mediate indirect defence of plants by attracting natural enemies of the attacking herbivores. Herbivore-induced plant volatiles (HIPVs) include terpenoids that play key roles in the attraction of

  1. Mechanisms and ecological implications of plant-mediated interactions between belowground and aboveground insect herbivores

    NARCIS (Netherlands)

    Papadopoulou, G.V.; Dam, N.M. van

    2017-01-01

    Plant-mediated interactions between belowground (BG) and aboveground (AG) herbivores have received increasing interest recently. However, the molecular mechanisms underlying ecological consequences of BG–AG interactions are not fully clear yet. Herbivore-induced plant defenses are complex and

  2. Smelling the wood from the trees: Non-linear parasitoid responses to volatile attractants produced by wild and cultivated cabbage

    NARCIS (Netherlands)

    Gols, R.; Bullock, J.M.; Dicke, M.; Bukovinszky, T.; Harvey, J.A.

    2011-01-01

    Despite a large number of studies on herbivore-induced plant volatiles (HIPVs), little is known about which specific compounds are used by natural enemies to locate prey- or host- infested plants. In addition, the role of HIPVs in attracting natural enemies has been restricted largely to

  3. Information use by the predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae), a specialised natural enemy of herbivorous spider mites

    NARCIS (Netherlands)

    Boer, de J.G.; Dicke, M.

    2005-01-01

    Plants can respond to infestation by herbivores with the emission of specific herbivore-induced plant volatiles. Many carnivorous arthropods that feed on herbivorous prey use these volatiles to locate their prey. Despite the growing amount of research papers on the interactions in tritrophic

  4. A weevil sex pheromone serves as an attractant for its entomopathogenic nematode predators

    Science.gov (United States)

    Diaprepes abbreviatus is an invasive pest of citrus in the United States originating from the Caribbean. Entomopathogenic nematodes (EPNs) are used as biological control agents in the citrus agroecosystems against D. abbreviatus. EPNs respond to herbivore-induced volatiles from citrus roots to assis...

  5. How does Phytoseiulus Persimilis find its prey when foraging within a bean plant?

    DEFF Research Database (Denmark)

    Zemek, R.; Nachman, Gøsta Støger; Ru°z¿ic¿kova´, S

    The role of herbivore-induced volatile substances in prey-finding by phytoseiid mites has been repeatedly documented using an olfactometer. The objective of the present paper is to test the hypothesis that movement by Phytoseiulus persimilis is affected by these volatiles even on plants. Two seri...

  6. Evaluation of airborne methyl salicylate for improved conservation biological control of two-spotted spider mite and hop aphid in Oregon hop yards

    Science.gov (United States)

    The use of synthetic herbivore-induced plant volatiles (HIPV) to attract natural enemies has received interest as a tool to enhance conservation biological control (CBC). Methyl salicylate (MeSA) is a HIPV that is attractive to several key predators of two-spotted spider mite, Tetranychus urticae K...

  7. Evaluation of airborne methyl salicylate for improved conservation biological control of two-spotted spider mites and hop aphid in Oregon hop yards

    Science.gov (United States)

    The use of synthetic herbivore-induced plant volatiles (HIPV) to attract natural enemies has received interest as a tool to enhance conservation biological control (CBC). Methyl salicylate (MeSA) is a HIPV that is attractive to several key predators of two-spotted spider mite, Tetranychus urticae K...

  8. Foraging behaviour of parasitoids in multi-herbivore communities

    NARCIS (Netherlands)

    Rijk, de M.

    2016-01-01

    Foraging behaviour of parasitoids in multi-herbivore communities Parasitic wasps, or parasitoids, use herbivore-induced plant volatiles and infochemicals produced directly by the herbivore to locate their herbivorous hosts. This process could be interrupted by the presence of

  9. Ecological costs and benefits correlated with trypsin protease inhibitor production in Nicotiana attenuata

    NARCIS (Netherlands)

    Glawe, G.A.; Zavala, J.A.; Kessler, A.; Van Dam, N.M.; Baldwin, I.T.

    2003-01-01

    Genotypes of the wild tobacco Nicotiana attenuata from different geographic regions in North America vary considerably in the level of constitutive and inducible trypsin protease inhibitors (TrypPIs), a potent direct defense, as well as in the production of herbivore-induced volatiles that function

  10. Qualitative and quantitative variation between volatile profiles induced by Tetranychus urticae feeding on different plants of various families

    NARCIS (Netherlands)

    Boom, van den C.E.M.; Beek, van T.A.; Posthumus, M.A.; Groot, de Æ.; Dicke, M.

    2004-01-01

    Many plant species are known to emit herbivore-induced volatiles in response to herbivory. The spider mite Tetranychus urticae Koch is a generalist that can feed on several hundreds of host plant species. Volatiles emitted by T. urticae-infested plants of 11 species were compared: soybean (Glycine

  11. Prey and non-prey arthropods sharing a host plant : Effects on induced volatile emission and predator attraction

    NARCIS (Netherlands)

    de Boer, Jetske G.; Hordijk, Cornelis A.; Posthumus, Maarten A.; Dicke, Marcel

    It is well established that plants infested with a single herbivore species can attract specific natural enemies through the emission of herbivore-induced volatiles. However, it is less clear what happens when plants are simultaneously attacked by more than one species. We analyzed volatile

  12. Prey and Non-prey Arthropods Sharing a Host Plant: Effects on Induced Volatile Emission and Predator Attraction

    NARCIS (Netherlands)

    de Boer, J.G.; Hordijk, C.A.; Posthumus, M.A.; Dicke, M.

    2008-01-01

    It is well established that plants infested with a single herbivore species can attract specific natural enemies through the emission of herbivore-induced volatiles. However, it is less clear what happens when plants are simultaneously attacked by more than one species. We analyzed volatile

  13. Variation in natural plant products and the attraction of bodyguards involved in indirect plant defense

    NARCIS (Netherlands)

    Mumm, R.; Dicke, M.

    2010-01-01

    Plants can respond to feeding or egg deposition by herbivorous arthropods by changing the volatile blend that they emit. These herbivore-induced plant volatiles (HIPVs) can attract carnivorous natural enemies of the herbivores, such as parasitoids and predators, a phenomenon that is called indirect

  14. Significance of terpenoids in induced indirect plant defence against herbivorous arthropods

    NARCIS (Netherlands)

    Mumm, R.; Posthumus, M.A.; Dicke, M.

    2008-01-01

    Many plants respond to herbivory by arthropods with an induced emission of volatiles such as green leaf volatiles and terpenoids. These herbivore-induced plant volatiles (HIPVs) can attract carnivores, for example, predators and parasitoids. We investigated the significance of terpenoids in

  15. Invasive insect herbivores as disrupters of chemically-mediated tritrophic interactions: effects of herbivore density and parasitoid learning

    Science.gov (United States)

    Invasive species of insect herbivores have the potential to interfere with native multitrophic interactions when they invade new environments. For instance, exotic herbivores can affect the chemical cues emitted by plants and disrupt attraction of natural enemies mediated by herbivore-induced plant ...

  16. Differential effects of jasmonic acid treatment of Brassica nigra on the attraction of pollinators, parasitoids, and butterflies

    NARCIS (Netherlands)

    Bruinsma, M.; IJdema, H.; Loon, van J.J.A.; Dicke, M.

    2008-01-01

    Herbivore-induced plant defences influence the behaviour of herbivores as well as that of their natural enemies. Jasmonic acid is one of the key hormones involved in both these direct and indirect induced defences. Jasmonic acid treatment of plants changes the composition of defence chemicals in the

  17. Feeding guild of non-host community members affects host-foraging efficiency of a parasitic wasp

    NARCIS (Netherlands)

    Rijk, de Marjolein; Yang, Daowei; Engel, Bastiaan; Dicke, Marcel; Poelman, Erik H.

    2016-01-01

    Interactions between predator and prey, or parasitoid and host, are shaped by trait-and density-mediated processes involving other community members. Parasitoids that lay their eggs in herbivorous insects locate their hosts through infochemicals such as herbivore-induced plant volatiles (HIPVs)

  18. Differential costs of two distinct resistance mechanisms induced by different herbivore species in Arabidopsis

    NARCIS (Netherlands)

    Onkokesung, Nawaporn; Reichelt, Michael; Doorn, van Arjen; Schuurink, R.C.; Dicke, Marcel

    2016-01-01

    Plants respond to herbivory with the induction of resistance, mediated by distinct phytohormonal signaling pathways and their interactions. Phloem feeders are known to induce plant resistance via the salicylic acid pathway, whereas biting-chewing herbivores induce plant resistance mainly via the

  19. Differential Costs of Two Distinct Resistance Mechanisms Induced by Different Herbivore Species in Arabidopsis

    NARCIS (Netherlands)

    Onkokesung, N.; Reichelt, M.; van Doorn, A.; Schuurink, R.C.; Dicke, M.

    2016-01-01

    Plants respond to herbivory with the induction of resistance, mediated by distinct phytohormonal signaling pathways and their interactions. Phloem feeders are known to induce plant resistance via the salicylic acid pathway, whereas biting-chewing herbivores induce plant resistance mainly via the

  20. Ambulatory responses of Laricobius nigrinus (Coleoptera: Derodontidae), a hemlock woolly adelgid predator, to odors from prey, host foliage, and feeding conspecifics.

    Science.gov (United States)

    Arielle Arsenault; Albert (Bud) Mayfield; Kimberly Wallin

    2015-01-01

    Behavioral interactions between insects and their environments are often mediated by volatile cues. Plant-produced chemical cues induced by herbivore activity are often more effective at attracting predators than are cues produced by the herbivore alone (Dicke and van Loon 2000). The presence of herbivore-induced plant volatiles makes foraging by predators more...

  1. Salivary proteins of spider mites suppress defenses in Nicotiana benthamiana and promote mite reproduction

    NARCIS (Netherlands)

    Villarroel, C.A.; Jonckheere, W.; Alba Cano, J.M.; Glas, J.J.; Dermauw, W.; Haring, M.A.; Van Leeuwen, T.; Schuurink, R.C.; Kant, M.R.

    2016-01-01

    Spider mites (Tetranychidae sp.) are widely occurring arthropod pests on cultivated plants. Feeding by the two-spotted spider mite T. urticae, a generalist herbivore, induces a defense response in plants that mainly depends on the phytohormones jasmonic acid and salicylic acid (SA). On tomato

  2. Morphology of the olfactory system in the predatory mite Phytoseiulus persimilis

    NARCIS (Netherlands)

    van Wijk, M.; Wadman, W.J.; Sabelis, M.W.

    2006-01-01

    The predatory mite Phytoseiulus persimilis locates its prey, the two-spotted spider mite, by means of herbivore-induced plant volatiles. The olfactory response to this quantitatively and qualitatively variable source of information is particularly well documented. The mites perform this task with a

  3. Federal Specification MMM-A-1617B for Adhesive, Rubber-Base, General-Purpose HAP-Free Replacement

    Science.gov (United States)

    2011-05-01

    classified into three types (3): • Type I: Non-oil-resistant natural rubber base, synthetic natural (polyisoprene), styrene butadiene (SBR), reclaim...or combinations. • Type II: Oil-resistant polychloroprene rubber base. • Type III: Fuel-resistant butadiene acrylonitrile (nitrile) rubber base...all contained a nitrile polymer base, also known as acrylonitrile butadiene . Nitrile has good resistance to oil, water, and heat. The adhesive

  4. Compatibility Studies on Elastomers and Polymers with Ethanol Blended Gasoline

    OpenAIRE

    Dhaliwal, J S; M. S. Negi; G. S. Kapur; Shashi Kant

    2014-01-01

    This paper reports the compatibility studies of 10% ethanol blended gasoline (E10) with four types of elastomer materials, namely, Neoprene rubber, Nitrile rubber, hydrogenated Nitrile butadiene rubber (HNBR), and Polyvinyl chloride/Nitrile butadiene rubber blend (PVC/NBR), and two types of plastic materials, namely, Nylon-66 and Polyoxymethylene (Delrin). These materials have applications in automotives as engine seals, gaskets, fuel system seals and hoses, and so forth. Two types of the eth...

  5. 40 CFR 442.2 - General definitions.

    Science.gov (United States)

    2010-07-01

    ..., organic chemicals including: alcohols, aldehydes, formaldehydes, phenols, peroxides, organic salts, amines..., glycerines, and organic polymers; refractory organic compounds including: ketones, nitriles, organo-metallic...

  6. Nickel-Catalyzed C–CN Bond Formation via Decarbonylative Cyanation of Esters, Amides, and Intramolecular Recombination Fragment Coupling of Acyl Cyanides

    KAUST Repository

    Chatupheeraphat, Adisak

    2017-08-07

    An efficient nickel-catalyzed decarbonylative cyanation reaction which allows the direct functional-group interconversion of readily available esters into the corresponding nitriles was developed. This reaction successfully offers access to structurally diverse nitriles with high efficiency and excellent functional-group tolerance and provides a good alternative to classical synthetic pathways from diazonium salts or organic halide compounds.

  7. Synthesis and Characterization of 5-Substituted 1H-Tetrazoles in the ...

    African Journals Online (AJOL)

    NICOLAAS

    the addition of azide ions to organic nitriles or cyanamides.11. Later Sharpless and co-workers reported an ... sized tetrazoles by the addition of TMSN3 to organic nitriles using 10 mol% TBAF as catalyst.13 Several .... mine the minimum fungicidal concentration (MFC) and mini- mum bactericidal concentration (MBC).

  8. Nitrilase-catalysed conversion of acrylonitrile by free and ...

    Indian Academy of Sciences (India)

    Prakash

    Nitrilase-catalysed conversion of acrylonitrile by free and immobilized cells of Streptomyces sp. 21. J. Biosci. 34(1), March 2009. 1. Introduction. Nitrilases that hydrolyse organic nitriles to carboxylic acids and ammonia are a commercially interesting group of enzymes, as nitriles are important intermediates in the chemical ...

  9. Synthesis of 4-[10H-Phenothiazin-10-yl(1H-tetrazol-5-yl-methyl]phenol

    Directory of Open Access Journals (Sweden)

    Bathey R. Venkatraman

    2009-09-01

    Full Text Available This present work aims at synthesizing a novel tetrazole from phenothiazine. Phenothiazine is converted into a nitrile by reacting it with 4-hydroxybenzaldehyde, sodium metabisulphite and sodium cyanide. The nitrile on treatment with NaN3/DMF yielded the corresponding tetrazole. The tetrazole obtained was characterized by IR, 1H NMR, EI-MS and elemental analysis.

  10. Solvent induced supramolecular anisotropy in molecular gels

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Michael A., E-mail: mroger09@uoguelph.ca [Department of Food Science, University of Guelph, Guelph, Ontario, N3C3X9 (Canada); Corradini, Maria G. [Department of Food Science, University of Massachusetts Amherst, Amherst, MA, 01003 (United States); Emge, Thomas [Department of Chemistry and Biochemistry, Rutgers University, New Brunswick, NJ, 08901 (United States)

    2017-06-15

    Herein is the first report of solvent induced anisotropy in 12-hydroxystearic acid self-assembled fibrillar networks. Increasing the chain length of polar solvent, such as nitriles and ketones, tailored the anisotropy of the fibrillar aggregates. 12HSA molecular gels, comprised of alkanes, exhibited an isotropic fibrillar network irrespective of the alkane chain length. In polar solvents, anisotropy, observed using 2D powder x-ray diffraction profiles, is correlated to a fibrillar supramolecular morphologies in long chain nitriles and ketones while sphereulitic crystals are correlated to x-ray diffraction patterns with an isotropic scatter intensity in short chain ketones and nitriles. These changes directly modify the final physical properties of the gels. - Highlights: • 12-HSA self-assembles into crystalline supramolecular morphologies depending on the solvent. • Alkanes, short chain nitriles and ketones led to 12-HSA displaying supramolecular isotropy. • In long chain nitriles and ketones, 12-HSA displays supramolecular anisotropy.

  11. Efficacy of feeding glucosinolate-extracted crambe meal to broiler chicks.

    Science.gov (United States)

    Kloss, P; Jeffrey, E; Wallig, M; Tumbleson, M; Parsons, C; Johnson, L; Reuber, M

    1994-10-01

    Glucosinolates and their breakdown products (nitriles) have long been implicated as toxic factors when feeding rapeseed (Brassica napus) meals and crambe (Crambe abyssinica) meals to poultry. Accordingly, various methods have been developed to remove these compounds from the meals to enhance their value as feed supplements. Glucosinolates and nitriles were extracted from commercially processed, defatted crambe meal by washing with water or various solvent-water mixtures: 50% isopropanol, 50% acetone, or 50% ethanol. In addition, crambe seed was extruded and extracted in the laboratory with isopropanol or hexane. Water washing of commercially defatted meal proved to be the most effective method of extraction, removing 95% of the glucosinolates and nitriles. Meals were fed to 7-d-old broiler chicks at 10% of the diet for 14 d. Weight gain decreased (P glucosinolate content. Feed intake also decreased (P glucosinolate or nitrile intake. A relationship (P glucosinolate intake. No correlation was found between feed intake and meal glucosinolate or nitrile concentrations.

  12. Changes in cytokinins are sufficient to alter developmental patterns of defense metabolites in Nicotiana attenuata

    Czech Academy of Sciences Publication Activity Database

    Bruetting, C.; Schaefer, N.; Vaňková, Radomíra; Gase, K.; Baldwin, I.T.; Meldau, S.

    2017-01-01

    Roč. 89, č. 1 (2017), s. 15-30 ISSN 0960-7412 R&D Projects: GA MŠk LD14120 Institutional support: RVO:61389030 Keywords : proteinase-inhibitor production * plant defense * arabidopsis-thaliana * leaf senescence * insect interactions * tobacco plant s * jasmonic acid * manduca-sexta * cis-zeatin * responses * cytokinins * optimal defense * herbivores * inducible defense * Nicotiana attenuata * Manduca sexta * plant development * immunosenescence * phytohormones Subject RIV: ED - Physiology Impact factor: 5.901, year: 2016

  13. Avaliação da incorporação de resíduo de poli(etileno-co-acetato de vinila em borracha nitrílica Evaluation of waste poly(ethylene-co-vinyl incorporation in nitrile rubber

    Directory of Open Access Journals (Sweden)

    Viviane X. Moreira

    2003-01-01

    Full Text Available A influência do resíduo de poli(etileno-co-acetato de vinila (EVAR no desempenho mecânico de composições vulcanizadas de NBR foi estudada. A concentração ótima de EVAR, a qual apresentou maior valor de tensão na ruptura, foi de 50 phr. Além disso, a influência do EVA e do EVAR funcionalizado com grupos tióis (EVALSH e do EVAR modificado com anidrido maleico (EVARCO como agentes compatibilizantes foi estudada. O copolímero EVALSH atuou como acelerador no processo de vulcanização, sendo observado um decréscimo do tempo de vulcanização. Uma melhora na resistência ao envelhecimento também foi observada. A adição de 10 phr de EVARCO resultou na redução do tempo de vulcanização e em uma melhora na maior parte das propriedades avaliadas. As propriedades termodinâmico-mecânicas foram avaliadas por análises de DMTA. Os estudos da interação entre a fase dispersa e a fase matriz foram realizados utilizando-se microscopia eletrônica de varredura (MEV.The influence of poly(ethylene-co-vinyl acetate (EVA waste (EVAR on the mechanical performance of NBR vulcanisates compounds was studied. The optimum concentration of EVAR, which has presented higher ultimate tensile stress, was found at 50 phr. In addition, the influence of EVA and EVAR functionalized with mercaptan groups (EVALSH and EVAR functionalized with maleic anidride (EVARCO as compatibilizing agents was studied. The copolymer EVALSH acted as accelerator for the curing system, since a decreasing of the curing time was observed. An improvement of ageing resistance was also observed. The addition of EVARCO resulted in a reduction of the curing time and an improvement of most of evaluated properties. The thermodynamic-mechanic properties were investigated by DMTA analysis. The studies on the interaction between dispersed phase and matrix were performed by scanning electron microscopy (SEM.

  14. Impact of thermal processing on sulforaphane yield from broccoli (Brassica oleracea L. var. italica)

    Science.gov (United States)

    In broccoli, sulforaphane forms when the glucosinolate glucoraphanin is hydrolyzed by the endogenous plant thiohydrolase myrosinase. A myrosinase cofactor directs hydrolysis away from formation of bioactive sulforaphane and toward an inactive product, sulforaphane nitrile. The cofactor is more hea...

  15. Polymer Coating of Carbon Nanotube Fibers for Electric Microcables

    National Research Council Canada - National Science Library

    Alvarez, Noe; Ochmann, Timothy; Kienzle, Nicholas; Ruff, Brad; Haase, Mark; Hopkins, Tracy; Pixley, Sarah; Mast, David; Schulz, Mark; Shanov, Vesselin

    2014-01-01

    .... Ideally, a flexible insulator such as hydrogenated nitrile butadiene rubber (HNBR) on the CNT fiber can allow fabrication of CNT coils that can be assembled into lightweight, corrosion resistant...

  16. Anodic oxidation of bis(9,9-. beta. -cyanoethyl)fluorene: an efficient way for synthesizing a new functionalizable conducting polymer

    Energy Technology Data Exchange (ETDEWEB)

    Le Deit, H.; Rault-Berthelot, J.; Simonet, J. (Lab. d' Electrochimie Organique, Univ. de Rennes 1, 35 (France))

    1992-06-01

    The title compound can be easily polymerized by anodic means in CH{sub 2}Cl{sub 2} leading to a new polyfluorene possessing nitrile groups potentially functionalizable by classical chemical means. (orig.).

  17. Enzymatic stereoselective synthesis of B-amino acids

    CSIR Research Space (South Africa)

    Chhiba, V

    2014-06-01

    Full Text Available , antimicrobials, and as nonstandard amino acids in therapeutic peptides or peptidomimetics. Access to these compounds can be achieved through diverse synthetic routes with enantioselective steps catalyzed in different ways, including by means of nitrile hydrolysis...

  18. IRIS Toxicological Review of Acrylonitrile (External Review Draft)

    Science.gov (United States)

    [UPDATE] New Schedule for IRIS Acrylonitrile Assessment In May 2012, EPA developed a new schedule for completing the IRIS acrylonitrile assessment. Acrylonitrile is primarily used in the manufacture of acrylic and modacrylic fibers, plastics, and nitrile rubbers. It ...

  19. Fire retardant polyisocyanurate foam

    Science.gov (United States)

    Riccitiello, S. R.; Parker, J. A.

    1972-01-01

    Fire retardant properties of low density polymer foam are increased. Foam has pendant nitrile groups which form thermally-stable heterocyclic structures at temperature below degradation temperature of urethane linkages.

  20. Using the Estimating Supplies Program to Develop Materiel Solutions for the U.S. Air Force Aeromedical Evacuation In-Flight Kit (FFQDM)

    Science.gov (United States)

    2008-07-07

    ONEWAY STRAIGHT SMALL 50S EA 6515009269201 CONNECTOR TUBING STRAIGHT 50S EA 6515015257142 FILTER EXHALATION UNIVERSAL HEPA EA 6515013543969...PAD BED LINEN NONWOVEN DISP 23X36IN 150S EA 7350004441323 STRAW DRINKING 400S EA 6515013520446 SYRINGE HYPO GP 60ML LUER TIP W/O NDL 120S EA... FILTER ME SUCTION CANNISTER 10S EA 6515014618929 GLOVE EXAM NITRILE L 100S EA 6515014618933 GLOVE EXAM NITRILE M 100S EA 6515015316051 SUCTION

  1. Acetonitrile Ion Suppression in Atmospheric Pressure Ionization Mass Spectrometry.

    Science.gov (United States)

    Colizza, Kevin; Mahoney, Keira E; Yevdokimov, Alexander V; Smith, James L; Oxley, Jimmie C

    2016-11-01

    Efforts to analyze trace levels of cyclic peroxides by liquid chromatography/mass spectrometry gave evidence that acetonitrile suppressed ion formation. Further investigations extended this discovery to ketones, linear peroxides, esters, and possibly many other types of compounds, including triazole and menadione. Direct ionization suppression caused by acetonitrile was observed for multiple adduct types in both electrospray ionization and atmospheric pressure chemical ionization. The addition of only 2% acetonitrile significantly decreased the sensitivity of analyte response. Efforts to identify the mechanism were made using various nitriles. The ion suppression was reduced by substitution of an acetonitrile hydrogen with an electron-withdrawing group, but was exacerbated by electron-donating or steric groups adjacent to the nitrile. Although current theory does not explain this phenomenon, we propose that polar interactions between the various functionalities and the nitrile may be forming neutral aggregates that manifest as ionization suppression. Graphical Abstract ᅟ.

  2. Can plant-natural enemy communication withstand disruption by biotic and abiotic factors?

    Science.gov (United States)

    Clavijo McCormick, Andrea

    2016-12-01

    The attraction of natural enemies towards herbivore-induced plant volatiles is a well-documented phenomenon. However, the majority of published studies are carried under optimal water and nutrient regimes and with just one herbivore. But what happens when additional levels of ecological complexity are added? Does the presence of a second herbivore, microorganisms, and abiotic stress interfere with plant-natural enemy communication? or is communication stable enough to withstand disruption by additional biotic and abiotic factors?Investigating the effects of these additional levels of ecological complexity is key to understanding the stability of tritrophic interactions in natural ecosystems and may aid to forecast the impact of environmental disturbances on these, especially in climate change scenarios, which are often associated with modifications in plant and arthropod species distribution and increased levels of abiotic stress.This review explores the literature on natural enemy attraction to herbivore-induced volatiles when, besides herbivory, plants are challenged by additional biotic and abiotic factors.The aim of this review was to establish the impact of different biotic and abiotic factors on plant-natural enemy communication and to highlight critical aspects to guide future research efforts.

  3. Complex odor from plants under attack: herbivore's enemies react to the whole, not its parts.

    Directory of Open Access Journals (Sweden)

    Michiel van Wijk

    Full Text Available Insect herbivory induces plant odors that attract herbivores' natural enemies. Assuming this attraction emerges from individual compounds, genetic control over odor emission of crops may provide a rationale for manipulating the distribution of predators used for pest control. However, studies on odor perception in vertebrates and invertebrates suggest that olfactory information processing of mixtures results in odor percepts that are a synthetic whole and not a set of components that could function as recognizable individual attractants. Here, we ask if predators respond to herbivore-induced attractants in odor mixtures or to odor mixture as a whole.We studied a system consisting of Lima bean, the herbivorous mite Tetranychus urticae and the predatory mite Phytoseiulus persimilis. We found that four herbivore-induced bean volatiles are not attractive in pure form while a fifth, methyl salicylate (MeSA, is. Several reduced mixtures deficient in one component compared to the full spider-mite induced blend were not attractive despite the presence of MeSA indicating that the predators cannot detect this component in these odor mixtures. A mixture of all five HIPV is most attractive, when offered together with the non-induced odor of Lima bean. Odors that elicit no response in their pure form were essential components of the attractive mixture.We conclude that the predatory mites perceive odors as a synthetic whole and that the hypothesis that predatory mites recognize attractive HIPV in odor mixtures is unsupported.

  4. Tetranychus urticae-triggered responses promote genotype-dependent conspecific repellence or attractiveness in citrus.

    Science.gov (United States)

    Agut, Blas; Gamir, Jordi; Jaques, Josep A; Flors, Victor

    2015-08-01

    The citrus rootstocks sour orange and Cleopatra mandarin display differential resistance against Tetranychus urticae. Sour orange plants support reduced oviposition, growth rates and damage compared with Cleopatra mandarin plants. Jasmonic acid signalling and flavonoid accumulation have been revealed as key mechanisms for the enhanced resistance of sour orange plants. In this study, we observed that the release of T. urticae herbivore-induced plant volatiles (HIPVs) from sour orange plants has a marked repellent effect on conspecific mites associated with the production of the terpenes α-ocimene, α-farnesene, pinene and d-limonene, and the green leaf volatile 4-hydroxy-4-methyl-2-pentanone. By contrast, T. urticae HIPVs from Cleopatra mandarin plants promote conspecific mite attraction associated with an increase in (2-butoxyethoxy) ethanol, benzaldehyde and methyl salicylate levels. HIPVs released from sour orange plants following T. urticae infestation induce resistance in Cleopatra mandarin plants, thereby reducing oviposition rates and stimulating the oxylipin biosynthetic gene lipoxygenase2 (LOX2). Cleopatra HIPVs do not affect the response to T. urticae of these rootstocks. We conclude that sour orange plants promote herbivore-induced resistance in Cleopatra mandarin plants and, despite the weak basal resistance of these rootstocks, herbivore resistance can be induced through the combination of HIPVs, such as α-ocimene and d-limonene. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  5. Behavioural and community ecology of plants that cry for help.

    Science.gov (United States)

    Dicke, Marcel

    2009-06-01

    Plants respond to insect herbivory with the production of volatiles that attract carnivorous enemies of the herbivores, a phenomenon called indirect defence or 'plants crying for help'. Plants are under selection to maximize Darwinian fitness, and this can be done by making the right 'decisions' (i.e. by responding to environmental stress in ways that maximize seed production). Plant decisions related to the response to herbivory in terms of the emission of herbivore-induced volatiles include 'to respond or not to respond', 'how fast to respond', 'how to respond' and 'when to stop responding'. In this review, the state-of-the-art of the research field is presented in the context of these decisions that plants face. New questions and directions for future research are identified. To understand the consequences of plant responses in a community context, it is important to expand research from individual interactions to multispecies interactions in a community context. To achieve this, detailed information on underlying mechanisms is essential and first steps on this road have been made. This selective review addresses the ecology of herbivore-induced plant volatiles (HIPVs) by integrating information on mechanisms and ecological functions. New questions are identified as well as challenges for extending current information to community ecology.

  6. Simultaneous inbreeding modifies inbreeding depression in a plant-herbivore interaction.

    Science.gov (United States)

    Kalske, Aino; Mutikainen, Pia; Muola, Anne; Scheepens, J F; Laukkanen, Liisa; Salminen, Juha-Pekka; Leimu, Roosa

    2014-02-01

    Because inbreeding is common in natural populations of plants and their herbivores, herbivore-induced selection on plants, and vice versa, may be significantly modified by inbreeding and inbreeding depression. In a feeding assay with inbred and outbred lines of both the perennial herb, Vincetoxicum hirundinaria, and its specialist herbivore, Abrostola asclepiadis, we discovered that plant inbreeding increased inbreeding depression in herbivore performance in some populations. The effect of inbreeding on plant resistance varied among plant and herbivore populations. The among-population variation is likely to be driven by variation in plant secondary compounds across populations. In addition, inbreeding depression in plant resistance was substantial when herbivores were outbred, but diminished when herbivores were inbred. These findings demonstrate that in plant-herbivore interactions expression of inbreeding depression can depend on the level of inbreeding of the interacting species. Furthermore, our results suggest that when herbivores are inbred, herbivore-induced selection against self-fertilisation in plants may diminish. © 2013 John Wiley & Sons Ltd/CNRS.

  7. Jasmonic acid carboxyl methyltransferase regulates development and herbivory-induced defense response in rice.

    Science.gov (United States)

    Qi, Jinfeng; Li, Jiancai; Han, Xiu; Li, Ran; Wu, Jianqiang; Yu, Haixin; Hu, Lingfei; Xiao, Yutao; Lu, Jing; Lou, Yonggen

    2016-06-01

    Jasmonic acid (JA) and related metabolites play a key role in plant defense and growth. JA carboxyl methyltransferase (JMT) may be involved in plant defense and development by methylating JA to methyl jasmonate (MeJA) and thus influencing the concentrations of JA and related metabolites. However, no JMT gene has been well characterized in monocotyledon defense and development at the molecular level. After we cloned a rice JMT gene, OsJMT1, whose encoding protein was localized in the cytosol, we found that the recombinant OsJMT1 protein catalyzed JA to MeJA. OsJMT1 is up-regulated in response to infestation with the brown planthopper (BPH; Nilaparvata lugens). Plants in which OsJMT1 had been overexpressed (oe-JMT plants) showed reduced height and yield. These oe-JMT plants also exhibited increased MeJA levels but reduced levels of herbivore-induced JA and jasmonoyl-isoleucine (JA-Ile). The oe-JMT plants were more attractive to BPH female adults but showed increased resistance to BPH nymphs, probably owing to the different responses of BPH female adults and nymphs to the changes in levels of H2 O2 and MeJA in oe-JMT plants. These results indicate that OsJMT1, by altering levels of JA and related metabolites, plays a role in regulating plant development and herbivore-induced defense responses in rice. © 2015 Institute of Botany, Chinese Academy of Sciences.

  8. A novel approach for the synthesis of 5-substituted-1H-tetrazoles

    Energy Technology Data Exchange (ETDEWEB)

    Akhlaghinia, Batool; Rezazadeh, Soodabeh, E-mail: akhlaghinia@um.ac.ir [Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

    2012-12-15

    A series of 5-substituted-1H-tetrazoles (RCN{sub 4}H) have been synthesized by cycloaddition reaction of different aryl and alkyl nitriles with sodium azide in DMSO using CuSO{sub 4}{center_dot}5H{sub 2}O as catalyst. A wide variety of aryl nitriles underwent [3+2] cycloaddition to afford tetrazoles under mild reaction conditions in good to excellent yields. The catalyst used is readily available and environmentally friendly. Short reaction times, good to excellent yields, safe process and simple workup make this method an attractive and useful contribution to present organic synthesis of 5-substituted-1H-tetrazoles. (author)

  9. Green and selective synthesis of N-substituted amides using water soluble porphyrazinato copper(II) catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Ghodsinia, Sara S.E.; Akhlaghinia, Batool; Eshghi, Hossein, E-mail: akhlaghinia@um.ac.ir [Ferdowsi University of Mashhad (Iran, Islamic Republic of). Faculty of Sciences. Department of Chemistry; Safaei, Elham [Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of). Department of Chemistry

    2013-06-15

    N, N',N{sup ,} N{sup '}-Tetramethyl tetra-2,3-pyridinoporphyrazinato copper(II) methyl sulfate ([Cu(2,3-tmtppa)](MeSO{sub 4}){sub 4}) efficiently catalyzed the direct conversion of nitriles to N-substituted amides. The one pot selective synthesis of the N-substituted amides from nitriles and primary amines was performed in refluxing H{sub 2}O. The catalyst was recovered and reused at least four times, maintaining its efficiency. (author)

  10. Sulforaphane formation and bioaccessibility are more affected by steaming time than meal composition during in vitro digestion of broccoli

    NARCIS (Netherlands)

    Sarvan-Kruse, Irmela; Kramer, E.; Bouwmeester, Hans; Dekker, Matthijs; Verkerk, R.

    2017-01-01

    Broccoli is a rich source of the glucosinolate glucoraphanin (GR). After hydrolysis of GR by the endogenous enzyme myrosinase, sulforaphane (SF) or sulforaphane nitrile (SFN) are produced, depending on environmental conditions. How the conversion of GR and bioaccessibility of released breakdown

  11. Lutidine-derived Ru-CNC hydrogenation pincer catalysts with versatile coordination properties

    NARCIS (Netherlands)

    Filonenko, Georgy A.; Cosimi, Elena; Lefort, Laurent; Conley, Matthew P.; Copéret, Christophe; Lutz, Martin; Hensen, Emiel J M; Pidko, Evgeny A.

    2014-01-01

    Lutidine-derived bis-N-heterocyclic carbene (NHC) ruthenium CNC-pincer complexes (Ru-CNC's) were prepared. Depending on the synthetic procedure, normal (1, 2) or mixed normal/abnormal NHC-complexes (3) are formed. In the presence of phosphazene base, Ru-CNC complexes activate nitriles to give

  12. Study of Plasma Chemistry and Plasma Processing.

    Science.gov (United States)

    1983-01-01

    fr at east art the products Sn rai- decreased indicates that factor a is dominant. When nitrile and ethane are the major products and radical mixtures... fomento and aceo cnitrileo from pouene and succinonitrile, 110-61-2; bicvclohexyl, 4233-18-5; 8-d4, 80866-20-2.1 cyanogen, where methyl radicals are

  13. Solid-phase synthesis of 3-amino-2-pyrazolines

    DEFF Research Database (Denmark)

    Nielsen, John

    1998-01-01

    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to alpha,beta-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2...

  14. Solid-phase synthesis of 3-amino-2-pyrazolines

    DEFF Research Database (Denmark)

    Lyngsø, Lars O.; Nielsen, John

    1998-01-01

    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to α,β-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2- pyrazolines....

  15. Acylation of Grignard reagents mediated by N-methylpyrrolidone: a remarkable selectivity for the synthesis of ketones.

    Science.gov (United States)

    Gowda, Maravanhalli Sidde; Pande, Sushanth Sudhir; Ramakrishna, Ramesha Andagar; Prabhu, Kandikere Ramaiah

    2011-08-07

    An efficient user-friendly method of acylation of Grignard reagents to selectively synthesize ketones is presented, which is assisted by simple amides such as NMP, or DMF. The present chemoselective method tolerates a variety of functional groups such as ketone, ester, nitrile and other functional groups.

  16. Optimizing isothiocyanate formation during enzymatic glucosinolate breakdown by adjusting pH value, temperature and dilution in Brassica vegetables and Arabidopsis thaliana

    NARCIS (Netherlands)

    Hanschen, F.; Klopsch, R.; Oliviero, T.; Schreiner, M.; Verkerk, R.; Dekker, M.

    2017-01-01

    Consumption of glucosinolate-rich Brassicales vegetables is associated with a decreased risk of cancer with enzymatic hydrolysis of glucosinolates playing a key role. However, formation of health-promoting isothiocyanates is inhibited by the epithiospecifier protein in favour of nitriles and

  17. One-pot synthesis of new series 3, 4, 5-trisubstituted ...

    Indian Academy of Sciences (India)

    Abstract. We have synthesized a series of novel isoxazolines via 1,3-dipolar cycloaddition reaction. Aromatic aldoximes undergo oxidative-dehydrogenation with chloramine-T to give nitrile oxides, which were reacted with chalcones to afford of 3,4,5-trisubstituted 4,5-dihydroisoxazolines in a good yield.

  18. Nitrilase-catalysed conversion of acrylonitrile by free and ...

    Indian Academy of Sciences (India)

    The biotransformation of acrylonitrile was investigated using thermophilic nitrilase produced from a new isolate Streptomyces sp. MTCC 7546 in both the free and immobilized state. Under optimal conditions, the enzyme converts nitriles to acids without the formation of amides. The whole cells of the isolate were immobilized ...

  19. Magnetron reactively sputtered Ti-DLC coatings on HNBR rubber : The influence of substrate bias

    NARCIS (Netherlands)

    Bui, X.L.; Pei, Y.T.; Hosson, J.Th.M. De

    2008-01-01

    In this study, Ti-containing diamond-like carbon (Ti-DLC) coatings have been deposited on HNBR (hydrogenated nitrile butadiene) rubber and also on Si wafer as reference via unbalanced magnetroli reactive sputtering from a Ti target in C2H2/Ar plasma. The deposition rates of coatings on rubber and Si

  20. Tribological behavior of W-DLC coated rubber seals

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Zhou, X.B.; Hosson, J.Th.M. De

    2008-01-01

    Tungsten-containing diamond-like carbon (W-DLC) coatings have been deposited on FKM (fluorocarbon) and HNBR (hydrogenated nitrile butadiene) rubbers via unbalanced magnetron reactive sputtering from a WC target in a C2H2/Ar plasma. The surface morphology and fracture cross sections of uncoated and

  1. Modification of rubber surface with hydrogenated diamond-like carbon thin films

    NARCIS (Netherlands)

    Pei, Y. T.; Bui, X. L.; De Hosson, J. Th. M.; Laudon, M; Romanowicz, B

    2009-01-01

    Thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) for reduction of friction and enhancement of wear resistance of dynamic rubber seals, by sputtering graphite targets in C(2)H(2)/Ar plasma. The wax removal and pre-deposition

  2. Modification of rubber surface with DLC thin films for low friction and self lubrication

    NARCIS (Netherlands)

    Bui, X. L.; Pei, Y. T.; Mulder, E. D. G.; De Hosson, J. Th. M.; DeHosson, JTM; Brebbia, CA

    2009-01-01

    Thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) via magnetron-enhanced plasma chemical vapor deposition (ME-PCVD). Pre-deposition plasma treatment of HNBR substrate is proven to be crucial for the improvement of film

  3. Microstructure and tribological performance of diamond-like carbon films deposited on hydrogenated rubber

    NARCIS (Netherlands)

    Pal, J.P. van der; Martinez Martinez, Diego; Pei, Y.T.; Rudolf, P.; Hosson, J.Th.M. De

    2012-01-01

    In this paper, the microstructure and tribological performance of diamond-like carbon (DLC) films prepared by plasma chemical vapor deposition on hydrogenated nitrile butadiene rubbers (HNBR) are studied. Different negative variations of temperature during film growth were selected by proper changes

  4. Deposition and characterization of hydrogenated diamond-like carbon thin films on rubber seals

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Hosson, J.Th.M. De

    2010-01-01

    Thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) for reduction of friction and enhancement of wear resistance of dynamic rubber seals. The wax removal and pre-deposition plasma treatment of HNBR substrates are proven to be

  5. Flexible diamond-like carbon films on rubber : On the origin of self-acting segmentation and film flexibility

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Pal, J.P. van der; Martinez-Martinez, D.; Zhou, X.B.; Hosson, J.Th.M. De

    This paper reports an experimental approach to deposit flexible diamond-like carbon (DLC) films on hydrogenated nitrile butadiene rubber (HNBR) with plasma-assisted chemical vapor deposition and an analytical model to describe the self-segmentation mechanism of the DLC films. By making use of the

  6. Microstructure and tribological behavior of tungsten-containing diamondlike carbon coated rubbers

    NARCIS (Netherlands)

    Pei, Y.T.; Bui, X.L.; Zhou, Xiao; Hosson, J.Th.M. De

    2008-01-01

    Tungsten-containing diamondlike carbon (W-DLC) coatings have been deposited on FKM (fluorocarbon), ACM (acrylate), and HNBR (hydrogenated nitrile butadiene) rubbers via unbalanced magnetron reactive sputtering from a WC target in C2H2/Ar plasma. The surface morphology and, fracture cross sections of

  7. Adhesion improvement of hydrogenated diamond-like carbon thin films by pre-deposition plasma treatment of rubber substrate

    NARCIS (Netherlands)

    Bui, X.L.; Pei, Y.T.; Mulder, E.D.G.; Hosson, J.Th.M. De

    2009-01-01

    For reduction of friction and enhancement of wear resistance of dynamic rubber seals, thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) via magnetron-enhanced plasma chemical vapor deposition (ME-PCVD). Pre-deposition plasma

  8. Nafion®-catalyzed microwave-assisted Ritter reaction: An atom-economic solvent-free synthesis of amides

    Science.gov (United States)

    An atom-economic solvent-free synthesis of amides by the Ritter reaction of alcohols and nitriles under microwave irradiation is reported. This green protocol is catalyzed by solid supported Nafion®NR50 with improved efficiency and reduced waste production.

  9. Recent advances and challenges in the heterologous production of microbial nitrilases for biocatalytic applications

    Czech Academy of Sciences Publication Activity Database

    Martínková, Ludmila; Rucká, Lenka; Nešvera, Jan; Pátek, Miroslav

    2017-01-01

    Roč. 33, č. 1 (2017), s. 1-11, č. článku 8. ISSN 0959-3993 R&D Projects: GA MŠk(CZ) LD15107 Institutional support: RVO:61388971 Keywords : Aldoxime-nitrile pathway * Biocatalytic applications * Database mining Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 1.658, year: 2016

  10. Acylamidation of acetylenes

    Energy Technology Data Exchange (ETDEWEB)

    Gridnev, I.D.; Balenkova, E.S.

    1989-01-10

    The reactions of phenylacetylene, 1-heptyne, and diphenylacetylene with the complexes of acetylfluoroborate with acetonitrile and with chloroacetonitrile take place regiospecifically and stereospecifically as syn-addition of the acetyl group and nitrile at the triple bond of the acetylene and lead to previously unknown Z-N-acyl-/beta/-amino, /alpha/,/beta/-unsaturated ketones.

  11. Energy Level Tuning of Poly(phenylene-alt-dithienobenzothiadiazole)s for Low Photon Energy Loss Solar Cells

    NARCIS (Netherlands)

    Heuvel, R.; van Franeker, J. J.; Janssen, R. A. J.

    2017-01-01

    Six poly(phenylene-alt-dithienobenzothiadiazole)-based polymers have been synthesized for application in polymer–fullerene solar cells. Hydrogen, fluorine, or nitrile substitution on benzo­thiadiazole and alkoxy or ester substitution on the phenylene moiety are investigated to reduce the energy loss

  12. CHS129f4_online 771..773

    Indian Academy of Sciences (India)

    An efficient, eco-friendly, inexpensive and recyclable sulfated polyborate catalyst was used for the preparation of N-tert-butyl/N-trityl protected amides via Ritter reaction of various nitriles with tertiary alcohols. The key advantages of the present method are short reaction times, high yields, easy workup, recyclability of the ...

  13. Sulfated polyborate: A mild, efficient catalyst for synthesis of N ...

    Indian Academy of Sciences (India)

    Rapid, efficient and inexpensive method for synthesis of N-tert-butyl/N-trityl protected amides via Ritter reaction of nitriles with tertiary alcohols in the presence of a sulfated polyborate catalyst under solvent-free conditions is described. The catalyst has the advantage of Lewis as well as Bronsted acidity and recyclability ...

  14. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences. Venkateswara Rao Anna. Articles written in Journal of Chemical Sciences. Volume 124 Issue 2 March 2012 pp 411-419. and - cyclic -perimeter hydrocarbon platinum group metal complexes of 3-(2-pyridyl)pyrazole derived ligands with a pendant nitrile group: Syntheses ...

  15. η5 and η6 - cyclic π-perimeter hydrocarbon platinum group metal ...

    Indian Academy of Sciences (India)

    411–419. c Indian Academy of Sciences. η5 and η6. - cyclic π-perimeter hydrocarbon platinum group metal complexes of 3-(2-pyridyl)pyrazole derived ligands with a pendant nitrile group: Syntheses, spectral and structural studies. GLORIA SAIREMa, VENKATESWARA RAO ANNAa, PENG WANGb, BABULAL DASc and.

  16. A practical synthesis of (-)-kainic acid.

    Science.gov (United States)

    Takita, Satoshi; Yokoshima, Satoshi; Fukuyama, Tohru

    2011-04-15

    A highly practical stereoselective total synthesis of (-)-kainic acid is described. This synthesis features the stereoselective alkylation of an iodolactone intermediate that was efficiently prepared from (+)-carvone and introduction of carboxylic acid by hydrolysis of a nitrile accompanied by epimerizaion. This synthetic route enabled us to obtain 14.6 g of (-)-kainic acid. © 2011 American Chemical Society

  17. New Nitration Concepts

    Science.gov (United States)

    1987-09-01

    trometry (70 eV). Other characteristic fragmentations are~ desilylation reaction, giving 1-alkyl-2-nitroacetylene ccm - loss of an alkyl group from...potcntially useful as explosives, biocides, cyanide, which react with amines to give arnino nitriles, and pharmaceuticals , necessitating a high

  18. Measurement of Henry's Law Constants Using Internal Standards: A Quantitative GC Experiment for the Instrumental Analysis or Environmental Chemistry Laboratory

    Science.gov (United States)

    Ji, Chang; Boisvert, Susanne M.; Arida, Ann-Marie C.; Day, Shannon E.

    2008-01-01

    An internal standard method applicable to undergraduate instrumental analysis or environmental chemistry laboratory has been designed and tested to determine the Henry's law constants for a series of alkyl nitriles. In this method, a mixture of the analytes and an internal standard is prepared and used to make a standard solution (organic solvent)…

  19. Performance analysis of exam gloves used for aseptic rodent surgery.

    Science.gov (United States)

    LeMoine, Dana M; Bergdall, Valerie K; Freed, Carrie

    2015-05-01

    Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP-PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham 'exertion' activity. According to these criteria, 94% of HP-PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP-PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries.

  20. An efficient catalytic reductive amination: A facile one-pot access to ...

    Indian Academy of Sciences (India)

    A wide range of functional groups such as ester, nitro, nitrile, halogen, alkene, heterocycles were tolerated. Also, acid sensitive protecting groups like TBDMS and TBDPS were not affected. In addition, the present methodology was extended for tandem amination-amidation of 3-formyl-indole-2-carboxylic acids with ...

  1. Pd (OAc) 2/DPPF-catalysed microwave-assisted cyanide-free ...

    Indian Academy of Sciences (India)

    This study reports microwave-assisted cyanide-free synthesis of aryl nitriles from aryl halides using palladium acetate/1,1-bis(diphenylphosphino)ferrocene as a new catalyst system. Reported protocol is a rapid, cyanide-free, single step reaction, wherein formamide acts as a solvent as well as a source of cyanide. The use ...

  2. Magnetic Silica-Supported Ruthenium Nanoparticles: An Efficient Catalyst for Transfer Hydrogenation of Carbonyl Compounds

    Science.gov (United States)

    One-pot synthesis of ruthenium nanoparticles on magnetic silica is described which involve the in situ generation of magnetic silica (Fe3O4@ SiO2) and ruthenium nano particles immobilization; the hydration of nitriles and transfer hydrogenation of carbonyl compounds occurs in hi...

  3. An Approach to Preparation of trans-DHQs via Ring-Opening of meso-N-Sulfonylaziridines

    DEFF Research Database (Denmark)

    Nolsøe, Jens Mortansson Jelstrup; Riegert, David; Müller, Paul

    2011-01-01

    As an approach to the enantioselective synthesis of trans-decahydroquinolines (DHQs), desymmetrization of meso-aziridine (5) with various carbon nucleophiles under catalytic conditions was investigated. By applying TMSCN in the presence of YbCl3 and chiral nonracemic ligands, nitrile 13 was obtai...

  4. Rh-Catalyzed Anti-Markovnikov Hydrocyanation of Terminal Alkynes.

    Science.gov (United States)

    Ye, Fei; Chen, Junting; Ritter, Tobias

    2017-05-31

    We report the first highly stereo- and regioselective hydrocyanation of terminal alkynes to furnish E-configured alkenyl nitriles. Acrylonitriles can be accessed on gram scale with broad substrate scope and functional group tolerance. The hydrocyanation reaction employs acetone cyanohydrin as a practical alternative to HCN gas.

  5. Synthèse et réactivité des dérivés de la quinoléine : préparation des isoxazoles et isoxazolines quinoléiques par des réactions de cycloaddition 1,3-dipolaires

    Directory of Open Access Journals (Sweden)

    N. BELLOULA

    2015-03-01

    Full Text Available The main objectif of this work is the synthesis of new five-membred heterocycles containing the quinoline moeity via a 1,3-dipolar cycloadition reaction of nitrile oxide with dipolariphiles in goal of discover a new compounds potentially actives in different domains notably in pharmacy and biology.

  6. Dependence of Some Mechanical Properties of Elastic Bands on the Length and Load Time

    Science.gov (United States)

    Triana, C. A.; Fajardo, F.

    2012-01-01

    We present a study of the maximum stress supported by elastics bands of nitrile as a function of the natural length and the load time. The maximum tension of rupture and the corresponding variation in length were found by measuring the elongation of an elastic band when a mass is suspended from its free end until it reaches the breaking point. The…

  7. Diastereoselective self-assembly of dinuclear heterochiral metallosupramolecular rhombs in a self-discriminating process.

    Science.gov (United States)

    Weilandt, Torsten; Kiehne, Ulf; Schnakenburg, Gregor; Lützen, Arne

    2009-05-07

    A racemic bis(nitrile) ligand based on the Tröger's base scaffold self-assembles into an achiral dinuclear heterochiral rhomb in a diastereoselective self-discrimination process; this occurs upon coordination to (dppp)Pd(OTf)(2) as evidenced by nmr spectroscopy and X-ray crystal structure analysis.

  8. Nitrilase enzymes and their role in plant-microbe interactions.

    Science.gov (United States)

    Howden, Andrew J M; Preston, Gail M

    2009-07-01

    Nitrilase enzymes (nitrilases) catalyse the hydrolysis of nitrile compounds to the corresponding carboxylic acid and ammonia, and have a wide range of industrial and biotechnological applications, including the synthesis of industrially important carboxylic acids and bioremediation of cyanide and toxic nitriles. Nitrilases are produced by a wide range of organisms, including plants, bacteria and fungi, but despite their biotechnological importance, the role of these enzymes in living organisms is relatively underexplored. Current research suggests that nitrilases play important roles in a range of biological processes. In the context of plant-microbe interactions they may have roles in hormone synthesis, nutrient assimilation and detoxification of exogenous and endogenous nitriles. Nitrilases are produced by both plant pathogenic and plant growth-promoting microorganisms, and their activities may have a significant impact on the outcome of plant-microbe interactions. In this paper we review current knowledge of the role of nitriles and nitrilases in plants and plant-associated microorganisms, and discuss how greater understanding of the natural functions of nitrilases could be applied to benefit both industry and agriculture. © 2009 The Authors. Journal compilation © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.

  9. An efficient and convenient synthesis of N-substituted amides under ...

    Indian Academy of Sciences (India)

    An efficient and inexpensive synthesis of N-substituted amides from the reaction of aliphatic and aromatic nitriles with various benzylic alcohols (secondary and tertiary) and tert-butyl alcohol by refluxing nitromethane via the Ritter reaction catalyzed by aluminum hydrogen sulfate [Al(HSO4)3] is described. Thecatalyst which ...

  10. 78 FR 56150 - Airworthiness Directives; Piper Aircraft, Inc. Airplanes

    Science.gov (United States)

    2013-09-12

    ...-018-AD; Amendment 39-17489; AD 2013-13-01] RIN 2120-AA64 Airworthiness Directives; Piper Aircraft, Inc...-01 applies to certain Piper Aircraft, Inc. Models PA-46-310P, PA-46-350P, PA-46R-350T, and PA-46... modifying and eventually replacing the fuel vent valves if the nitrile parts are installed for certain Piper...

  11. An efficient and convenient synthesis of N-substituted amides under ...

    Indian Academy of Sciences (India)

    scopic reagents, low yield, tedious product isolation, longer reaction time and competing side reactions. In this paper we wish to report a comprehensive study of the reactions between various organic nitriles and alcohols in the presence of catalytic amount of Al(HSO4)3 to provide N-substituted amides via Ritter fashion.

  12. Tetrameric DABCO™-Bromine: an Efficient and Versatile Reagent ...

    African Journals Online (AJOL)

    Tetrameric DABCO™-bromine is a powerful brominating agent but shows reasonable selectivity with certain substrates. The selective bromination for activated aromatic compounds and alkenes is reported. Synthesis of -bromo ketones and nitriles has also been achieved by using this reagent and the results are also ...

  13. Enzymatic halogenation and oxidation using an alcohol oxidase-vanadium chloroperoxidase cascade

    NARCIS (Netherlands)

    But, Andrada; Noord, Van Aster; Poletto, Francesca; Sanders, Johan P.M.; Franssen, Maurice C.R.; Scott, Elinor L.

    2017-01-01

    The chemo-enzymatic cascade which combines alcohol oxidase from Hansenula polymorpha (AOXHp) with vanadium chloroperoxidase (VCPO), for the production of biobased nitriles from amino acids was investigated. In the first reaction H2O2 (and acetaldehyde) are generated from ethanol and oxygen by AOXHp.

  14. Synthesis of 3,4-Dibenzyltetrahydrofuran Lignans (9,9′-Epoxylignanes

    Directory of Open Access Journals (Sweden)

    Kristiina Wähälä

    2013-10-01

    Full Text Available Different strategies for the racemic or enantiospecific total syntheses of plant and mammalian 3,4-dibenzyltetrahydrofuran lignans are reviewed and compared. The multi-step approaches have various key step strategies: Diels–Alder reactions, Stobbe condensations, Michael additions, alkylations, nitrile oxide cycloadditions, radical cyclisations, dianion and oxidative couplings.

  15. 1-[1-(4-Nitrophenylethylidene]thiosemicarbazide

    Directory of Open Access Journals (Sweden)

    Yu-Feng Ding

    2008-09-01

    Full Text Available The title compound, C9H10N4O2S, was prepared by the reaction of 1-(4-nitrophenylethanone and thiosemicarbazide in ethanol at 367 K. There are weak intermolecular N—H...S and N—H...O hydrogen-bonding interactions in the crystal structure involving the amine and nitrile groups, respectively, as donors.

  16. Selection of Priority Hazardous Chemicals for Permeation Testing and Hazardous Chemical Spill Detection and Analysis.

    Science.gov (United States)

    1986-07-01

    to the increase in the number of PCB incidents reported to the NRC. Of the top 25 NRC spills- excluding asphalt , creosote, jet fuel, kerosene, and...keytones 12. Glycols and epoxides 13. Carboxylic acid and derivatives 14. Nitriles and isocyanates 15. Amines and imines 16. Organic sulfur compounds

  17. Impact of thermal processing on sulforaphane yield from broccoli ( Brassica oleracea L. ssp. italica).

    Science.gov (United States)

    Wang, Grace C; Farnham, Mark; Jeffery, Elizabeth H

    2012-07-11

    In broccoli, sulforaphane forms when the glucosinolate glucoraphanin is hydrolyzed by the endogenous plant thiohydrolase myrosinase. A myrosinase cofactor directs hydrolysis away from the formation of bioactive sulforaphane and toward an inactive product, sulforaphane nitrile. The cofactor is more heat sensitive than myrosinase, presenting an opportunity to preferentially direct hydrolysis toward sulforaphane formation through regulation of thermal processing. Four broccoli cultivars were microwave heated, boiled, or steamed for various lengths of time. Production of nitrile during hydrolysis of unheated broccoli varied among cultivars from 91 to 52% of hydrolysis products (Pinnacle > Marathon > Patriot > Brigadier). Boiling and microwave heating caused an initial loss of nitrile, with a concomitant increase in sulforaphane, followed by loss of sulforaphane, all within 1 min. In contrast, steaming enhanced sulforaphane yield between 1.0 and 3.0 min in all but Brigadier. These data are proof of concept that steaming for 1.0-3.0 min provides less nitrile and more sulforaphane yield from a broccoli meal.

  18. Unusual reaction of chloramine-T with araldoximes.

    Science.gov (United States)

    Padmavathi, V; Venugopal Reddy, K; Padmaja, A; Venugopalan, P

    2003-02-21

    Reaction of araldoximes with 4 equiv of chloramine-T in refluxing methanol produces N-(p-tolyl)-N-(p-tosyl)benzamides via addition of 2 equiv of chloramine-T to the intermediate nitrile oxide followed by extrusion of sulfur dioxide.

  19. Synthesis of new series of 4, 5-dihydroisoxazole-5-carboxylate ...

    Indian Academy of Sciences (India)

    A new series of 4,5-dihydroisoxazole-5-carboxylate derivatives were synthesized via [3+2] cycloaddition reaction between ethyl acrylate and nitrile oxide generated in situ in presence of Chloramine-T. The synthesized derivatives were characterized by Mass, IR and NMR Spectroscopy and their mesomorphic behavior were ...

  20. Nigerian Journal of Chemical Research Vol. 22, No. 1, 2017 70 ...

    African Journals Online (AJOL)

    MR. S. O. OWALUDE

    Nigerian Journal of Chemical Research. Vol. 22, No. 1, 2017. 70. Synthesis of new ruthenium(II) complexes containing isocyanide and labile nitrile ligands. Owalude,* S. O., Tella, A. C. Eke, U. B. and Odebunmi, E. O.. Department of Chemistry, University of Ilorin, P.M.B. 1515, Ilorin, Nigeria. E-mail for correspondence: ...

  1. Elevated CO{sub 2} levels and herbivore damage alter host plant preferences

    Energy Technology Data Exchange (ETDEWEB)

    Agrell, J. [Lund Univ., Dept. of Animal Ecology, Lund (Sweden); Anderson, Peter, Swedish Univ. of Agricultural Sciences, Dept. of Crop Sciences, Alnarp (SE)); Oleszek, W.; Stochmal, Anna [Inst. of Soil Science and Plant Cultivation, Dept. of Biochemistry, Pulawy (Poland); Agrell, Cecilia [Lund Univ., Dept. of Chemical Ecology and Ecotoxicology, Lund (Sweden)

    2006-01-01

    Interactions between the moth Spodoptera littoralis and two of its host plants, alfalfa (Medicago sativa) and cotton (Gossypium hirsutum) were examined, using plants grown under ambient (350 ppm) and elevated (700 ppm) CO{sub 2} conditions. To determine strength and effects of herbivore-induced responses assays were performed with both undamaged (control) and herbivore damaged plants. CO{sub 2} and damage effects on larval host plant preferences were determined through dual-choice bioassays. In addition, larvae were reared from hatching to pupation on experimental foliage to examine effects on larval growth and development. When undamaged plants were used S. littoralis larvae in consumed more cotton than alfalfa, and CO{sub 2} enrichment caused a reduction in the preference for cotton. With damaged plants larvae consumed equal amounts of the two plant species (ambient CO{sub 2} conditions), but CO{sub 2} enrichment strongly shifted preferences towards cotton, which was then consumed three times more than alfalfa. Complementary assays showed that elevated CO{sub 2} levels had no effect on the herbivore-induced responses of cotton, whereas those of alfalfa were significantly increased. Larval growth was highest for larvae fed undamaged cotton irrespectively of CO{sub 2} level, and lowest for larvae on damaged alfalfa from the high CO{sub 2} treatment. Development time increased on damaged cotton irrespectively of CO{sub 2} treatment, and on damaged alfalfa in the elevated CO{sub 2} treatment. (au) These results demonstrate that elevated CO2 levels can cause insect herbivores to alter host plant preferences, and that effects on herbivore-induced responses may be a key mechanism behind these processes. Furthermore, since the insects were shown to avoid foliage that reduced their physiological performance, our data suggest that behavioural host plant shifts result in partial escape from negative consequences of feeding on high CO2 foliage. Thus, CO2 enrichment can alter

  2. A randomized control hands-on defibrillation study-Barrier use evaluation.

    Science.gov (United States)

    Wampler, David; Kharod, Chetan; Bolleter, Scotty; Burkett, Alison; Gabehart, Caitlin; Manifold, Craig

    2016-06-01

    Chest compressions and defibrillation are the only therapies proven to increase survival in cardiac arrest. Historically, rescuers must remove hands to shock, thereby interrupting chest compressions. This hands-off time results in a zero blood flow state. Pauses have been associated with poorer neurological recovery. This was a blinded randomized control cadaver study evaluating the detection of defibrillation during manual chest compressions. An active defibrillator was connected to the cadaver in the sternum-apex configuration. The sham defibrillator was not connected to the cadaver. Subjects performed chest compressions using 6 barrier types: barehand, single and double layer nitrile gloves, firefighter gloves, neoprene pad, and a manual chest compression/decompression device. Randomized defibrillations (10 per barrier type) were delivered at 30 joules (J) for bare hand and 360J for all other barriers. After each shock, the subject indicated degree of sensation on a VAS scale. Ten subjects participated. All subjects detected 30j shocks during barehand compressions, with only 1 undetected real shock. All barriers combined totaled 500 shocks delivered. Five (1%) active shocks were detected, 1(0.2%) single layer of Nitrile, 3(0.6%) with double layer nitrile, and 1(0.2%) with the neoprene barrier. One sham shock was reported with the single layer nitrile glove. No shocks were detected with fire gloves or compression decompression device. All shocks detected barely perceptible (0.25(±0.05)cm on 10cm VAS scale). Nitrile gloves and neoprene pad prevent (99%) responder's detection of defibrillation of a cadaver. Fire gloves and compression decompression device prevented detection. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Identifying qualitative effects of different grazing types on below-ground communities and function in a long-term field experiment

    DEFF Research Database (Denmark)

    Macdonald, Catriona A.; Crawley, Michael J.; Wright, Denis J.

    2015-01-01

    Herbivory is an important modulator of plant biodiversity and productivity in grasslands, but our understanding of herbivore-induced changes on below-ground processes and communities is limited. Using a long-term (17 years) experimental site, we evaluated impacts of rabbit and invertebrate grazers...... on some soil functions involved in carbon cycling, microbial diversity, structure and functional composition. Both rabbit and invertebrate grazing impacted soil functions and microbial community structure. All functional community measures (functions, biogeochemical cycling genes, network association...... between different taxa) were more strongly affected by invertebrate grazers than rabbits. Furthermore, our results suggest that exclusion of invertebrate grazers decreases both microbial biomass and abundance of genes associated with key biogeochemical cycles, and could thus have long-term consequences...

  4. Effect of Bt genetic engineering on indirect defense in cotton via a tritrophic interaction.

    Science.gov (United States)

    Moraes, Maria Carolina Blassioli; Laumann, Raul Alberto; Aquino, Michely Ferreira Santos; Paula, Débora Pires; Borges, Miguel

    2011-02-01

    We present a tritrophic analysis of the potential non-intended pleiotropic effects of cry1Ac gene derived from Bacillus thurigiensis (Bt) insertion in cotton (DeltaPine 404 Bt Bollgard® variety) on the emission of herbivore induced volatile compounds and on the attraction of the egg parasitoid Trichogramma pretisoum (Hymenoptera: Trichogrammatidae). Both the herbivore damaged Bt variety and its non-Bt isoline (DeltaPine DP4049 variety) produced volatiles in higher quantity when compared to undamaged plants and significantly attracted the egg parasitoids (T. pretiosum) when compared to undamaged plants. However, Trichogramma pretiosum did not differentiate between the transgenic and nontransgenic varieties, suggesting that the ratios between the compounds released by herbivory damaged -Bt cotton and herbivory damaged-non Bt cotton did not change significantly. Finally, no detrimental effect of the Bt genetic engineering was detected related to the volatile compounds released by Bollgard cotton on the behavior of the natural enemy studied.

  5. Maize plants prime anti-herbivore responses by the memorizing and recalling of airborne information in their genome.

    Science.gov (United States)

    Sugimoto, Koichi; Arimura, Gen-ichiro

    2013-10-01

    Intact maize plants prime for defensive action against herbivory in response to herbivore-induced plant volatiles (HI PVs) emitted from caterpillar-infested conspecific plants. The recent research showed that the primed defense in receiver plants that had been exposed to HI PVs was maintained for at least 5 d after exposure. Herbivory triggered the receiver plants to enhance the expression of a defense gene for trypsin inhibitor (TI ). At the upstream sequence of a TI gene, non-methylated cytosine residues were observed in the genome of HI PV-exposed plants more frequently than in that of healthy plant volatile-exposed plants. These findings provide an innovative mechanism for the memory of HI PV-mediated habituation for plant defense. This mechanism and further innovations for priming of defenses via plant communications will contribute to the development of plant volatile-based pest management methods in agriculture and horticulture.

  6. Localization of sesquiterpene formation and emission in maize leaves after herbivore damage

    Directory of Open Access Journals (Sweden)

    Köllner Tobias G

    2013-01-01

    Full Text Available Abstract Background Maize (Zea mays L. leaves damaged by lepidopteran herbivores emit a complex volatile blend that can attract natural enemies of the herbivores and may also have roles in direct defense and inter- or intra-plant signaling. The volatile blend is dominated by sesquiterpenes of which the majority is produced by two herbivore-induced terpene synthases, TPS10 and TPS23. However, little is known about the pattern of volatile emission within maize leaves. Results In this study, we restricted herbivore feeding to small sections of the maize leaf with the aim of determining the patterns of volatile sesquiterpene emission throughout the damaged leaf and in neighboring leaves. Sesquiterpene volatiles were released at high rates from damaged leaves, but at much lower rates from neighboring leaves. Release was restricted to the site of damage or to leaf sections located apical to the damage, but was not seen in sections basal to the damage or on the other side of the midrib. The emission pattern correlated well with the transcript pattern of the respective sesquiterpene synthase genes, tps10 and tps23, implying that biosynthesis likely occurs at the site of emission. The concentrations of jasmonic acid and its leucine derivative were also elevated in terpene-emitting tissues suggesting a role for jasmonates in propagating the damage signal. Conclusions In contrast to other defense reactions which often occur systemically throughout the whole plant, herbivore-induced sesquiterpene production in maize is restricted to the wounding site and distal leaf parts. Since the signal mediating this reaction is directed to the leaf tip and cannot propagate parallel to the leaf axis, it is likely connected to the xylem. The increasing gradient of volatiles from the tip of the leaf towards the damage site might aid herbivore enemies in host or prey finding.

  7. Beckmann rearrangement of oxime obtained from oleanolic acid. Structure elucidation of the initial oxime

    Science.gov (United States)

    Bednarczyk-Cwynar, Barbara; Zaprutko, Lucjusz; Froelich, Anna

    2013-12-01

    Seven-membered A-lactam and A-nitrile of methyl oleanolate were synthesized from the corresponding oxime. Many reaction setups were tried to find the optimum conditions. The best results (the highest yield of the desired lactam along with total consumption of starting oxime) were obtained in pyridine with phosphoryl chloride as Lewis acid. The main product was obtained with the yield of about 60%. Mechanism of Beckmann rearrangement for the above triterpenic 3-oxime leading to normal and abnormal product (a lactam and a nitrile, respectively) was explained. The structures of both products were determined and fully characterized by spectral data. The stereoisomerism of the initial oxime was determined on the basis of Beckmann rearrangement product structure and X-ray analysis.

  8. Beckmann rearrangement within the ring C of oleanolic acid lactone: Synthesis, structural study and reaction mechanism analysis

    Science.gov (United States)

    Froelich, Anna; Bednarczyk-Cwynar, Barbara; Zaprutko, Lucjusz; Gzella, Andrzej

    2017-05-01

    Synthesis, spectral and X-ray analysis of three compounds, i.e. 3β-acetoxy-12-hydroxyimino-18β-oleanan-28,13β-olide (substrate) and 3β-acetoxy-12-nitrile-12,13-seco-15(14 → 13)-abeoolean-14(27)-en-28,13β-olide and 3β-acetoxy-12-oxo-12a-aza-C-homoolean-13(18)-en-28-oic acid (Beckmann rearrangement reaction products) are described. Structural analysis revealed that the oxime group in the ring C in substrate molecule had an E-configuration. The nitrile product with retained lactone group was a result of major transformations within rings C and D of oleanane skeleton. In lactam product free carboxyl group and a double bond in ring D instead of lactone system were formed in Beckmann rearrangement reaction.

  9. Methods of making organic compounds by metathesis

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Timothy W.; Kaido, Hiroki; Lee, Choon Woo; Pederson, Richard L.; Schrodi, Yann; Tupy, Michael John

    2015-09-01

    Described are methods of making organic compounds by metathesis chemistry. The methods of the invention are particularly useful for making industrially-important organic compounds beginning with starting compositions derived from renewable feedstocks, such as natural oils. The methods make use of a cross-metathesis step with an olefin compound to produce functionalized alkene intermediates having a pre-determined double bond position. Once isolated, the functionalized alkene intermediate can be self-metathesized or cross-metathesized (e.g., with a second functionalized alkene) to produce the desired organic compound or a precursor thereto. The method may be used to make bifunctional organic compounds, such as diacids, diesters, dicarboxylate salts, acid/esters, acid/amines, acid/alcohols, acid/aldehydes, acid/ketones, acid/halides, acid/nitriles, ester/amines, ester/alcohols, ester/aldehydes, ester/ketones, ester/halides, ester/nitriles, and the like.

  10. Studies on polynuclear furoquinones. Part 1: Synthesis of tri- and tetra-cyclic furoquinones simulating BCD/ABCD ring system of furoquinone diterpenoids

    Directory of Open Access Journals (Sweden)

    Faruk H. Shaik

    2009-09-01

    Full Text Available Synthesis of phenanthro[1,2-b]furan-10,11-dione, the core nucleus present in Tanshinone-I is described in 8–10 steps starting from 2-bromo-3,4-dihydro-1-naphthaldehyde. The bromoaldehyde was converted to methyl 2-(2-bromo-1-naphthylacetate or 2-(2-bromo-1-naphthylacetonitrile following the protocol of functional group transformations. Subsequent Suzuki coupling of this ester/nitrile derivative with furan-2-boronic acid produced [2-(2-furyl-1-naphthyl]acetic ester/nitrile which on hydrolysis furnished the corresponding acid derivative. Cyclization of the acid followed by oxidation of the phenol, with Fremy’s salt, produced the tetra-cyclic furoquinone, phenanthro[1,2-b]furan-10,11-dione. This method has also been extended for the synthesis of the tricyclic furoquinone, naphtho[1,2-b]furan-4,5-dione.

  11. OSU-6: A Highly Efficient, Metal-Free, Heterogeneous Catalyst for the Click Synthesis of 5-Benzyl and 5-Aryl-1H-tetrazoles

    Directory of Open Access Journals (Sweden)

    Baskar Nammalwar

    2015-12-01

    Full Text Available OSU-6, an MCM-41 type hexagonal mesoporous silica with mild Brönsted acid properties, has been used as an efficient, metal-free, heterogeneous catalyst for the click synthesis of 5-benzyl and 5-aryl-1H-tetrazoles from nitriles in DMF at 90 °C. This catalyst offers advantages including ease of operation, milder conditions, high yields, and reusability. Studies are presented that demonstrate the robust nature of the catalyst under the optimized reaction conditions. OSU-6 promotes the 1,3-dipolar addition of azides to nitriles without significant degradation or clogging of the nanoporous structure. The catalyst can be reused up to five times without a significant reduction in yield, and it does not require treatment with acid between reactions.

  12. Dermal in vitro penetration of methiocarb, paclobutrazol, and pirimicarb: effect of nonylphenolethoxylate and protective gloves.

    Science.gov (United States)

    Nielsen, J B; Andersen, H R

    2001-02-01

    Dermal exposure has become the major route of human occupational exposure to pesticides. Detergents are used as part of formulated pesticide products and are known to change the barrier properties of human skin in vitro. However, studies on the influence of detergents as well as protective glove materials on dermal penetration of pesticides are scarce. In an experiment using in vitro static diffusion cells mounted with human skin, we evaluated the effect of nonylphenol-ethoxylate on dermal penetration of three extensively used pesticides--methiocarb, paclobutrazol, and pirimicarb--and the protection against dermal penetration offered by protective gloves made of latex or nitrile. There was a general tendency, though not statistically significant for all pesticides, for nonylphenolethoxylate to decrease the percutaneous penetration of the three pesticides. The nitrile generally offered better protection against percutaneous penetration of pesticides than did latex, but the degree of protection decreased over time and depended on the pesticides used.

  13. Functionalized isothianaphthene monomers that promote quinoidal character in donor-acceptor copolymers for organic photovoltaics

    KAUST Repository

    Douglas, Jessica D.

    2012-05-22

    A series of low band gap isothianaphthene-based (ITN) polymers with various electron-withdrawing substituents and intrinsic quinoidal character were synthesized, characterized, and tested in organic photovoltaic (OPV) devices. The three investigated ITN cores contained either ester, imide, or nitrile functionalities and were each synthesized in only four linear steps. The relative electron-withdrawing strength of the three substituents on the ITN moiety was evaluated and correlated to the optical and electronic properties of ITN-based copolymers. The ester- and imide-containing p-type polymers reached device efficiencies as high as 3% in bulk heterojunction blends with phenyl C 61-butyric acid methyl ester (PC 61BM), while the significantly electron-deficient nitrile-functionalized polymer behaved as an n-type material with an efficiency of 0.3% in bilayer devices with poly(3-(4-n-octyl)phenylthiophene) (POPT). © 2012 American Chemical Society.

  14. Properties of Elastomeric Composites with Functionalized Carbon Nanomaterial

    Science.gov (United States)

    Shashok, Zh. S.; Prokopchuk, N. R.; Vishnevskii, K. V.; Krauklis, A. V.; Borisevich, K. O.; Borisevich, I. O.; Zhdanok, S. A.

    2017-03-01

    The influence of two different nanomaterials on the properties of elastomeric composites based on general- and special-purpose rubbers has been investigated. For the elastomeric matrix, we used a combination of synthetic polyisopropene (SKI-3) and stereoregular butadiene (SKD) caoutchoucs in one case and butadiene-nitrile caoutchouc containing 27-30% of bound acrylic acid nitrile (BNKS-28) in the other case. For additives, nanomaterials of two types were used. To determine the degree of interaction of the additives with the elastomeric matrix, complex tests of rubber mixes and vulcanizates based on them were carried out, in which the following indices were determined: the Mooney viscosity, the relaxation and vulcanization characteristics of the mixes, the elastic-strength properties of the vulcanizates before and after thermal ageing, their resistance to thermal ageing, and the mechanical loss tangent.

  15. Synthesis, characterization and study of antibacterial activity of some novel tetrazole derivatives

    Directory of Open Access Journals (Sweden)

    Subramaniyan Arulmurugan

    2011-03-01

    Full Text Available This work aims at synthesizing novel tetrazole derivatives from phenothiazine. Phenothiazine is first converted into corresponding nitrile by reacting it with aldehyde, sodium metabisulphite and sodium cyanide. The nitrile on treatment with NaN3/DMF yielded the tetrazole derivative. In this work two tetrazole derivatives, viz., Dimethyl-{4-[phenothiazin-10-yl-(1H-tetrazol-5-ylmethyl]-phenyl}-amine and 10-[(4-Methoxy-phenyl-(1H-tetrazole-5-yl-methyl-10H-phenothiazine were prepared. The compounds were synthesized in good yields and their structures were confirmed by IR, 1H-NMR, mass and elemental analysis. The tetrazole compounds were screened for antimicrobial activity against bacteria and fungi. The results of the study show that the compounds present good antimicrobial activity.

  16. United abominations: Density functional studies of heavy metal chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Schoendorff, George [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    Carbonyl and nitrile addition to uranyl (UO22+) are studied. The competition between nitrile and water ligands in the formation of uranyl complexes is investigated. The possibility of hypercoordinated uranyl with acetone ligands is examined. Uranyl is studied with diactone alcohol ligands as a means to explain the apparent hypercoordinated uranyl. A discussion of the formation of mesityl oxide ligands is also included. A joint theory/experimental study of reactions of zwitterionic boratoiridium(I) complexes with oxazoline-based scorpionate ligands is reported. A computational study was done of the catalytic hydroamination/cyclization of aminoalkenes with zirconium-based catalysts. Techniques are surveyed for programming for graphical processing units (GPUs) using Fortran.

  17. Evidence of decline for Bufo boreas and Rana luteiventris in and around the northern Great Basin

    Science.gov (United States)

    Wente, W.; Adams, Michael J.; Pearl, Christopher A.

    2005-01-01

    A method is described for the analysis of polychlorinated biphenyl (PCB) compounds in tissue samples. Cleanup by hexane-aceto-nitrile partitioning and Florisil column chromatography are performed on samples before oxidative treatment to convert DDE to DCBP. PCB components are then determined semi-quantitatively by TLC. No prior separation of PCB from chlorinated pesticides is required. The lower limit of sensitivity is 0.2 ?g.

  18. Acta Aeronautica et Astronautica Sinica (Selected Articles),

    Science.gov (United States)

    1984-01-30

    Using the diglycidyl ether of biphenol A--butadiene-acrylo- nitrile rubber with random carboxyl groups--2-ethyl-4-methylimi- dazol epoxy resin system as...4 The results of the study showed that after being modified by butadiene rubber with a random carboxyl group and biphenol A, the fracture surface...energy of the biphenol A epoxy resin was increased by 1-4 times. The 106 impact strength was increased by 2-10 times. The toughness modu- lus (the area

  19. Testing of gloves for permeability to UV-curable acrylate coatings

    Energy Technology Data Exchange (ETDEWEB)

    Huggins, R.; Levy, N.; Pruitt, P.M.

    1987-07-01

    The handling of UV-curable acrylate formulations used in the coating of optical fiber requires protective measures to prevent contact dermatitis and/or allergic dermatitis. To characterize the permeability of various glove materials to a UV-curable acrylate coating, a study was undertaken using a modification of a standard ASTM permeability test, which demonstrated that nitrile rubber gloves provided the best protection of those glove materials tested.

  20. Testing of gloves for permeability to UV-curable acrylate coatings.

    Science.gov (United States)

    Huggins, R; Levy, N; Pruitt, P M

    1987-07-01

    The handling of UV-curable acrylate formulations used in the coating of optical fiber requires protective measures to prevent contact dermatitis and/or allergic dermatitis. To characterize the permeability of various glove materials to a UV-curable acrylate coating, a study was undertaken using a modification of a standard ASTM permeability test, which demonstrated that nitrile rubber gloves provided the best protection of those glove materials tested.

  1. A hydrophilic inorganic framework based on a sandwich polyoxometalate: unusual chemoselectivity for aldehydes/ketones with in situ generated hydroxylamine.

    Science.gov (United States)

    Xing, Songzhu; Han, Qiuxia; Shi, Zhuolin; Wang, Shugai; Yang, PeiPei; Wu, Qiang; Li, Mingxue

    2017-09-12

    A hydrophilic inorganic porous catalyst was prepared via the hydrothermal method. The combination of [WZn3(H2O)2(ZnW9O34)2](12-) and Co(ii) provides a synergistical catalytic way to promote oximation of aldehyde/ketone with in situ generated hydroxylamine that initially produces an oxime, which further either dehydrates into a nitrile or undergoes a Beckmann rearrangement to form an amide.

  2. Isoxazole derivatives as new nitric oxide elicitors in plants

    Directory of Open Access Journals (Sweden)

    Anca Oancea

    2017-04-01

    Full Text Available Several 3,5-disubstituted isoxazoles were obtained in good yields by regiospecific 1,3-dipolar cycloaddition reactions between aromatic nitrile oxides, generated in situ from the corresponding hydroxyimidoyl chlorides, with non-symmetrical activated alkynes in the presence of catalytic amounts of copper(I iodide. Effects of 3,5-disubstituted isoxazoles on nitric oxide and reactive oxygen species generation in Arabidopsis tissues was studied using specific diaminofluoresceine dyes as fluorescence indicators.

  3. Advances in enzyme immobilisation

    CSIR Research Space (South Africa)

    Brady, D

    2009-07-10

    Full Text Available substrate to fix the structure of cyclodextrin glycosyltransferases during rigidification by immobilisation, thereby enhancing the synthetic capability of the enzyme relative to its hydrolytic activity. In particular, modulation of enzyme... aggregates for enantioselective nitrile hydrolysis. Adv Synth Catal 349:2167- 2176 Kaulpiboon J, Pongsawasdi P, Zimmermann W (2007) Molecular imprinting of cyclodextrin glycosyltransferases from Paenibacillus sp. A11 and Bacillus macerans with γ-cyclodextrin...

  4. Lanthanide nitrates as Lewis acids in the one-pot synthesis of 1,2,4-oxadiazole derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Vale, Juliana A.; Faustino, Wagner M., E-mail: julianadqf@yahoo.com.br [Departamento de Quimica, Universidade Federal da Paraiba, Joao Pessoa, PB (Brazil); Zampieri, Davila de S.; Moran, Paulo J.S.; Rodrigues, Jose A.R. [Instituto de Quimica, Universidade Estadual de Campinas, SP (Brazil); Sa, Gilberto F. de [Departamento de Quimica Fundamental, CCEN, Universidade Federal de Pernambuco, Recife, PE (Brazil)

    2012-08-15

    In this work we report the use of lanthanide nitrates [Ln(NO{sub 3}){sub 3}] acting as catalyst in direct one pot synthesis of 3-benzoyl- and 3-acetyl-1,2,4-oxadiazoles derivatives from ketones, nitriles and nitric acid. This is the first example of one-pot synthesis of benzoyl- and acetyl 1,2,4-oxadiazoles derivatives preparation using acetophenones derivates with electron-donator groups. (author)

  5. The Effect of Switch-Loading Fuels on Fuel-Wetted Elastomers

    Science.gov (United States)

    2007-01-10

    be external. Because this seal is a nitrile-over-molded steel compression washer, if a leak were to develop, it could probably be stopped by...Pipelines Two types of coupled pipelines are utilized in the fuel distribution infrastructure: steel and aluminum. Steel pipes are grooved at...Department of Army, April 1995. 27. TM 10- 4320 -343-14, Military Technical Manual, “Fuel Pumping Assembly, Diesel Engine Driven, Wheel Mounted, 350

  6. Nano indium oxide as a recyclable catalyst for the synthesis of ...

    Indian Academy of Sciences (India)

    Synthesis of arylaminotetrazoles by the hydra- zoic acid. HN3, FeCl3-SiO2 and glacial HOAc, 1-(4-nitrophenyl)-. 5-amino-1H-tetrazole (isomer B) or a mixture of iso- mers (A + B) was obtained. The mechanism of the catalysis may originate from the nitrile group coordinating with the surface of the solid acid. The solid acid is ...

  7. Direct oxidation of Δ2-isoxazolines synthesis by metal ion-mediated diastereoface-selective 1,3-dipolar cycloaddition with “activated” DMSO

    OpenAIRE

    Naoufel Ben Hamadi; Moncef Msaddek

    2017-01-01

    A series of 4-hydroxyl-Δ2-isoxazol-6(6aH)-one derivatives was prepared by magnesium ion-mediated diastereoface-selective 1,3-dipolar cycloaddition of aromatic nitrile oxides with pyrrolidinone derivatives. The reaction of 4-hydroxyl-Δ2-isoxazol-6(6aH)-one derivatives with dimethylsulfoxide and oxalyl chloride under Swern conditions led to a Δ2-isoxazole-4,6(5H,6aH)-dione.

  8. Direct oxidation of Δ2-isoxazolines synthesis by metal ion-mediated diastereoface-selective 1,3-dipolar cycloaddition with “activated” DMSO

    Directory of Open Access Journals (Sweden)

    Naoufel Ben Hamadi

    2017-02-01

    Full Text Available A series of 4-hydroxyl-Δ2-isoxazol-6(6aH-one derivatives was prepared by magnesium ion-mediated diastereoface-selective 1,3-dipolar cycloaddition of aromatic nitrile oxides with pyrrolidinone derivatives. The reaction of 4-hydroxyl-Δ2-isoxazol-6(6aH-one derivatives with dimethylsulfoxide and oxalyl chloride under Swern conditions led to a Δ2-isoxazole-4,6(5H,6aH-dione.

  9. Copper-containing zeolite catalysts

    Science.gov (United States)

    Price, Geoffrey L.; Kanazirev, Vladislav

    1996-01-01

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  10. Reactions of Vanadocene-Carbyls with Carbon Monoxide, Xylylisocyanide and Carbon Dioxide

    NARCIS (Netherlands)

    Nieman, J.; Teuben, J.H.

    1985-01-01

    Vanadocene-allyl Cp2V(η1-C3H5) (1a) reacts with strong π-acceptor substrate ligands such as carbon monoxide, carbon dioxide and isonitriles. No reactions are observed with poorer π-acceptor substrates such as alkynes and nitriles. Reaction of 1a with CO gives Cp[η4-C5H5(C3H5)]V(CO)2, showing that

  11. Synthesis of β-Difluoroalkylated Acrylonitriles in the Presence of Copper Powder.

    Science.gov (United States)

    He, Yu-Tao; Li, Lian-Hua; Wang, Qiang; Wu, Wangsuo; Liang, Yong-Min

    2016-10-07

    A highly regio- and stereoselective copper-mediated cyanodifluoroalkylation of alkynes with ethyl difluoroiodoacetate and trimethylsilyl cyanide (TMSCN) is described. The three-component coupling reaction provides straightforward access to a variety of useful difluoroalkyl-substituted acrylonitriles. The introduction of the nitrile unit is of great importance in drug discovery for the modification of this fragment. Preliminary mechanistic investigations indicate that a vinyl iodide intermediate and a difluoroalkyl radical might be involved in this transformation.

  12. BF3·Et2O mediated one-step synthesis of N-substituted-1,2-dihydropyridines, indenopyridines and 5,6-dihydroisoquinolines.

    Science.gov (United States)

    Fathimath Salfeena, C T; Ashitha, K T; Sasidhar, B S

    2016-11-02

    A simple and efficient one-pot synthesis of N-substituted-1,2-dihydropyridines, indenopyridines and 5,6-dihydroisoquinolines by a BF3·Et2O mediated novel methodology, from easily available α,β-unsaturated ketones/arylidene ketones, phenyl acetylenes and substituted nitriles, has been described. This novel annulation provides quick access to complex polycyclic frameworks with an excellent substrate scope.

  13. Environmentally Friendly Adhesives and Sealants for Army Applications

    Science.gov (United States)

    2008-12-01

    styrene-butadiene rubber ( SBR ), and nitrile. One brush coat of the adhesive material was applied to the prepared surfaces of the rubber strips...Unclassified Title Environmentally Friendly Adhesives and Sealants for Army Applications 3. Author(s) Faye R. Toulan, Felicia Levine, Leslie...TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Environmentally Friendly Adhesives And Sealants For Army Applications 5a. CONTRACT NUMBER

  14. Fabrication of T142 Tank Track Pads for Evaluation of a Rubber-Kevlar Composite Compound

    Science.gov (United States)

    1982-06-01

    to improve the rubber - to-fiber bond. Several of these were investigated for this application . Bonding agents R-6 and M-3 were found to give the best...to dissolve or disperse the resorcinol be made in natural rubber , SBR , BR, IR, or Nitrile. component. Note: This Bonding Agent system has not yet been...PERIOD COVERED Fabrication of T142 Tank Track Pads for Evaluation of a Rubber -Kevlar Composite FINAL Compound S. PERFORMING ORG. REPORT NUMBER 7. AUTHOR

  15. Characterization and Neutralization of Recovered Lewisite Munitions

    Science.gov (United States)

    2006-12-01

    polyesters, acrylics, styrenes, furans, nitrile, natural rubber , SBR , and isoprene are not compatible with aqueous permanganate solutions.59-62...Hulet Jill L. Ruth Amanda M. Schenning U.S. ARMY MATERIALS AGENCY From Science to Solutions SCIENCE APPLICATIONS INTERNATIONAL CORPORATION Abingdon, MD...William R. Brankowitz and Edward F. Doyle (CMA-APG); and Dr. Arthur Denny [Science Applications International Corporation (SAIC)] for their helpful

  16. Characterization and Neutralization of Arsenical-Based WWII Era Chemical Munition Fills

    Science.gov (United States)

    2006-08-01

    permanganate solutions, with corrosion rates of 2 mpy or less. 63 Nylons, polyesters, acrylics, styrenes, furans, nitrile, natural rubber , SBR , and isoprene...EAI Corporation and GEO-CENTERS, which are now part of Science Applications International Corporation (SAIC). 14. ABSTRACT The purpose of this work... Applications International Corporation) for helpful discussions throughout this project. The authors also wish to thank Andy J. Murphy (U.S. Army Garrison

  17. Survey of dermal protection in Washington State collision repair industry.

    Science.gov (United States)

    Ceballos, Diana M; Fent, Kenneth W; Whittaker, Stephen G; Gaines, Linda G T; Thomasen, Jennifer M; Flack, Sheila L; Nylander-French, Leena A; Yost, Michael G; Reeb-Whitaker, Carolyn K

    2011-09-01

    Substantial exposure to isocyanates may occur during spray painting in autobody shops, yet information is lacking on the efficacy of the protective clothing used during spray painting. We investigated the personal and workplace factors associated with painters' dermal protection use during a large-scale exposure assessment study. Survey data indicated that 69% of painters always used gloves, with latex gloves (47%) and nitrile gloves (34%) used most frequently. Among latex glove users, 53% used thin latex (0.05-0.13 mm), 6% used medium latex (0.15-0.20 mm), and 12% used thick latex (> 0.20 mm). Among nitrile glove users, 27% used thin nitrile and 45% used medium nitrile. Sixty-three percent of painters always used coveralls, 44% preferring one particular brand. Although overspray presents an opportunity for dermal exposure to the neck and face, only 19% of painters protected these areas with personal protective equipment. Painters who always used coveralls were more likely to use gloves (odds ratio = 7.9, p = 0.061). Painters who reported ever having smoked cigarettes used gloves (p = 0.05) and coveralls (p = 0.04) more frequently. Painters who sprayed more than 34 clear coat jobs per month used coveralls most frequently (p = 0.038). Exact logistic regressions along with random sample calculations indicated that the survey results were independent of the shops. Because of the small sample size in this study, future research is warranted to corroborate these results. Studying the effectiveness of gloves and coveralls against polyurethane paints and understanding the underlying motivators and preferences for painters and business owners is needed for the development of best practices for the selection and use of dermal protection.

  18. European Science Notes. Volume 41, Number 7.

    Science.gov (United States)

    1987-07-01

    that can be computed from knowledge and understanding. Few areas the [objective and subjective] indicators in the social sciences have the history of...for their of potent environmental pollutants. Some ability to catalyze chemo - and enantio- examples are the conversion of nitriles selective...a staff of 14, taxonomy , and ecological research. Phys- nine at the professional level, who are ical and chemical oceanography are both investigating

  19. Hydroxyl and methoxyl derivatives of benzylglucosinolate in Lepidium densiflorum with hydrolysis to isothiocyanates and non-isothiocyanate products

    DEFF Research Database (Denmark)

    Pagnotta, Eleonora; Agerbirk, Niels; Olsen, Carl Erik

    2017-01-01

    isothiocyanates, the dominating 3,5-dimethoxysinalbin with a free p-hydroxyl group produced the corresponding alcohol and syringaldehyde (4-hydroxy-3,5-dimethoxybenzaldehyde). After thermal deactivation of the endogenous myrosinase enzyme, massive accumulation of the corresponding nitrile was detected. This case...... study points out how non-isothiocyanate glucosinolate hydrolysis products are prevalent in nature and of interest in both plant-pathogen interactions and human health....

  20. Semiquantitative determination of polychlorinated biphenyls in tissue samples by thin layer chromatography

    Science.gov (United States)

    Mulhern, B.M.; Cromartie, E.; Reichel, W.L.; Belisle, A.A.

    1971-01-01

    A method is described for the analysis of polychlorinated biphenyl (PCB) compounds in tissue samples. Cleanup by hexane-aceto-nitrile partitioning and Florisil column chromatography are performed on samples before oxidative treatment to convert DDE to DCBP. PCB components are then determined semi-quantitatively by TLC. No prior separation of PCB from chlorinated pesticides is required. The lower limit of sensitivity is 0.2 ?g.

  1. Remote meta C-H bond functionalization of 2-phenethylsulphonic acid and 3-phenylpropanoic acid derivatives.

    Science.gov (United States)

    Modak, Atanu; Mondal, Anirban; Watile, Rahul; Mukherjee, Semanti; Maiti, Debabrata

    2016-11-24

    This discovery illustrates selective meta C-H bond activation from multiple non-equivalent C-H bonds present in medicinally relevant arylethanesulfonic acid and the 2-arylpropanoic acid moiety using weakly coordinating nitrile as a directing group. Transformation of the meta olefinated compounds to important organic molecules has been demonstrated. Efforts were made to obtain mechanistic detail of the meta C-H bond functionalization reaction.

  2. Transformações químicas do (+-10b,14-diol-allo-aromadendrano, isolado de duguetia glabriuscula r. e. fries (r. e. fries (annonaceae e avaliações biológicas de alguns derivados obtidos Chemical modifications of (+-allo-aromadendrane-10b,14-diol isolated from duguetia glabriuscula r. e. fries (r. e. fries (annonaceae and biological evaluation of some obtained derivatives

    Directory of Open Access Journals (Sweden)

    Dênis Pires de Lima

    1997-12-01

    Full Text Available The sesquiterpene (+-allo-aromadendrane-10b-14-diol 1 was the lead compound to the preparation of several derivatives in order to test their biological activity against A. salina, C. sphaerospermum, E. coli and S. aureus. In this way the monoalcohols (+-viridiflorol 4, 9 and 11 were synthesized from 1 together with the acetal 6, the ketal 7, and the ketone 8. The oxirane 3 and nitrile 5 were also prepared using as an intermediate the tosylate derivative 2.

  3. Bioavailability of glucosinolates and their breakdown products

    DEFF Research Database (Denmark)

    Barba Orellana, Francisco Jose; Nikmaram, Nooshin; Roohinejad, Shahin

    2016-01-01

    cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates transit to the colon where they are hydrolyzed by the intestinal microbiota. Numerous factors, such as storage time, temperature, and atmosphere packaging, along with inactivation processes of myrosinase are influencing...... in the gut lumen. When cruciferous are consumed without processing, myrosinase enzyme present in these plants hydrolyzes the glucosinolates in the proximal part of the gastrointestinal tract to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. When...

  4. Glucosinolate degradation products, alkanes and fatty acids from plants and cell cultures of Descurainia sophia.

    Science.gov (United States)

    Afsharypuor, S; Lockwood, G B

    1985-12-01

    Allyl and 3-butenyl isothiocyanate with two nitriles and an epithiobutane derivative were estimated. These glucosinolate degradation products were found in callus, seed, and dried plant but not in suspension cultures. Seventeen alkanes and five fatty acids were also identified and estimated in plant material and cultures. 4-Methylthiobutyl and 2-phenylethyl isothiocyanates were also detected in seeds. Incubation of cultures at 4° increased levels of the fatty acids but not isothiocyanates.

  5. Evaluation of Dynamic Response and Brain Deformation Metrics for a Helmeted and Non-Helmeted Hybrid III Headform Using a Monorail Centric/Non-Centric Protocol

    OpenAIRE

    Nishizaki, Kyle; Marino, Wayne; Hoshizaki, Thomas Blaine; et al, ...

    2014-01-01

    Head injuries, and concussion in particular, have become a source of interest in the sport of ice hockey. This study proposes a monorail test methodology combined with a finite element method to evaluate ice hockey helmets in a centric/non-centric protocol with performance metrics more closely associated with risk of concussion. Two conditions were tested using the protocol: (a) helmeted versus no helmet, and (b) vinyl nitrile lined hockey helmet versus expanded polypropylene lined hockey hel...

  6. Investigation into the Impact of n-Decane, Decalin, and Isoparaffinic Solvent on Elastomeric Sealing Materials

    Directory of Open Access Journals (Sweden)

    Yue Liu

    2012-01-01

    Full Text Available One of the crucial aspects in the adoption of alternative fuels (e.g., GtL fuel in aviation industry is to investigate their compatibility with elastomeric materials used in current gas turbine engines. This study employed stress relaxation technique to investigate the effects of three solvents, namely, decalin (cycloparaffin, n-decane (normal paraffin, and ShellSol T solvent (isoparaffins on O-rings made from different materials. Results indicated that both fluorosilicone and fluorocarbon O-rings showed excellent compatibility with all 25 blends tested. The stress relaxation characteristic of nitrile O-ring was highly dependent on the composition of the solvents; the more decalin (n-decane is in the blend, the better (worse its sealing performance becomes. Effects of the three solvents presented in the tests indicated aromatics are not the only compounds that can swell nitrile O-ring. It is also important to notice that although decalin presents good O-ring swelling ability, it does not mean all cycloparaffins have the same property. n-decane also showed certain O-ring swelling ability but its main effect during the polymer-fuel interaction process is to extract materials out of nitrile O-ring. Isoparaffins do not participate in the O-ring swelling process. They only extract polymer materials; however, its extraction ability is relatively weaker than n-decane.

  7. Production of enantiomerically pure D-Phenylglycine using Pseudomonas aeruginosa 10145 as biocatalyst

    Directory of Open Access Journals (Sweden)

    F. O. M. Alonso

    2008-03-01

    Full Text Available Different bacterial strains were screened to detect nitrilase and/or nitrile hidratase/amidase activities towards benzonitrile, to be used as biocatalyst to produce enantiomerically pure non-proteinogenic amino acids using amino nitriles as starting material. The best biocatalyst found was Pseudomonas aeruginosa 10145, which showed high enzyme activities. Whole cells were used as catalyst for the transformation of 2-phenyl-2-amino-acetonitrile for the corresponding D-phenylglycine. The percentage conversion was followed by chiral HPLC. After 1 hour reaction 18% of 2-phenyl-2-amino-acetonitrile was converted into D-phenylglycine with an enantiomeric excess of over 95%. When an inducer was added to the media, an increase in nitrile hydrolyzing activities was detected, hence leading to total conversion of (R-2-phenyl-2-amino-acetonitrile to the corresponding amino acid in 30 min reaction. The isolated yield of the target product was 50% and its characterization was performed by polarimetry, chiral HPLC, IR-FT spectroscopy and GC-MS.

  8. Do clinical examination gloves provide adequate electrical insulation for safe hands-on defibrillation? II: Material integrity following exposure to defibrillation waveforms.

    Science.gov (United States)

    Petley, Graham W; Deakin, Charles D

    2013-07-01

    Maintaining contact with the patient during defibrillator discharge has been proposed as a method for reducing no flow time but carries an associated risk of electrocution of the rescuer. This study describes an investigation to determine if typical clinical examination gloves possess the dielectric strength needed to prevent breakdown at defibrillation voltages; a factor essential to protect the rescuer. Four types of examination glove typically used in a clinical environment were tested with two types of defibrillation waveform commonly used. For each type of glove, 10 samples were tested initially using a monophasic defibrillation waveform and then, using a fresh sample of gloves, with a Biphasic waveform. For each glove the number of shocks required before electrical breakdown occurred was recorded. Kimberly Clark KC300 (nitrile), Kimberly Clark KC500 purple (nitrile), PH Medisavers GN90 (nitrile) and Bodyguards GL6622 (Vinyl) were tested using a monophasic defibrillation waveform and broke down after a median of 1, 4.5, 1 and 1 shocks respectively. The equivalent values for Biphasic defibrillator were 2, >10, 2.5 and 1 shocks. Typical clinical examination gloves do not possess the dielectric strength required to protect a rescuer from defibrillation voltages during hands-on chest compressions. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Vibrational Stark Effect of the Electric-Field Reporter 4-Mercaptobenzonitrile as a Tool for Investigating Electrostatics at Electrode/SAM/Solution Interfaces

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    Peter Hildebrandt

    2012-06-01

    Full Text Available 4-mercaptobenzonitrile (MBN in self-assembled monolayers (SAMs on Au and Ag electrodes was studied by surface enhanced infrared absorption and Raman spectroscopy, to correlate the nitrile stretching frequency with the local electric field exploiting the vibrational Stark effect (VSE. Using MBN SAMs in different metal/SAM interfaces, we sorted out the main factors controlling the nitrile stretching frequency, which comprise, in addition to external electric fields, the metal-MBN bond, the surface potential, and hydrogen bond interactions. On the basis of the linear relationships between the nitrile stretching and the electrode potential, an electrostatic description of the interfacial potential distribution is presented that allows for determining the electric field strengths on the SAM surface, as well as the effective potential of zero-charge of the SAM-coated metal. Comparing this latter quantity with calculated values derived from literature data, we note a very good agreement for Au/MBN but distinct deviations for Ag/MBN which may reflect either the approximations and simplifications of the model or the uncertainty in reported structural parameters for Ag/MBN. The present electrostatic model consistently explains the electric field strengths for MBN SAMs on Ag and Au as well as for thiophenol and mercaptohexanoic acid SAMs with MBN incorporated as a VSE reporter.

  10. Molecular Modeling of the Poling of Piezoelectric Polyimides

    Science.gov (United States)

    Young, J. A.; Farmer, B. L.; Hinkley, J. A.

    1999-01-01

    The computational method described in this paper allows the calculation of the dielectric relaxation strength of an amorphous polymer based solely upon its chemical structure. The 4,4' oxydiphthalic anhydride (ODPA) dianhydride and bis-aminophenoxybenzene (APB) diamine based polyimides, (beta-CN) APB-ODPA and APB-ODPA were studied. Amorphous cells were constructed and then poled using molecular dynamics. Dielectric relaxation strengths of Delta(epsilon) = 17.8 for (beta-CN) APB-ODPA and Delta(epsilon) = 7.7 for APB-ODPA were predicted. These values are in excellent agreement with the experimental values. It was found that both the pendant nitrile dipole and the backbone anhydride residue dipole make significant contributions to the polyimides dielectric response. Specifically, it was shown that the difference in the magnitude of the dielectric relaxations is directly attributable to the nitrile dipole. The size of the relaxations indicate an absence of cooperative dipolar motions, The model was used to explain these results in terms of the average orientation of the nitrile and anhydride dipoles to within 51 deg. and 63 deg., respectively, of the applied electric field.

  11. Beta-heterosubstituted acrylonitriles--electronic structure study by UV-photoelectron spectroscopy and quantum chemical calculations.

    Science.gov (United States)

    Chrostowska, Anna; Nguyen, Thi Xuan Mai; Dargelos, Alain; Khayar, Saïd; Graciaa, Alain; Guillemin, Jean-Claude

    2009-03-19

    Beta-heterosubstituted acrylonitriles correspond to the formal addition of nucleophiles on cyanoacetylene. Acrylonitriles substituted with an amino, methoxy, mercapto group, or halogeno atom have been synthesized. Rearrangements between Z and E stereoisomers or tautomerizations have been studied by NMR spectroscopy and by quantum calculations. The photoelectron spectra were recorded and analyzed with the aid of a time-dependent density functional theory, ab initio OVGF, and so-called "corrected" ionization energy calculations. The electronic structure of the studied species was determined, and strong differences between beta-heterosubstituted acrylonitriles and the corresponding nitrile-free heteroalkenes were clearly documented. A "push-pull" effect was noticed, due to the combined donor effect of the substituent on one side of the carbon-carbon double bond and the electron-withdrawing effect of the nitrile group on the other side. Thus, the presence of a nitrile group strongly stabilizes the electronic structure. The efficient pi-donor contribution of the NH(2) and SH groups was evidenced.

  12. Compatibility Studies on Elastomers and Polymers with Ethanol Blended Gasoline

    Directory of Open Access Journals (Sweden)

    J. S. Dhaliwal

    2014-01-01

    Full Text Available This paper reports the compatibility studies of 10% ethanol blended gasoline (E10 with four types of elastomer materials, namely, Neoprene rubber, Nitrile rubber, hydrogenated Nitrile butadiene rubber (HNBR, and Polyvinyl chloride/Nitrile butadiene rubber blend (PVC/NBR, and two types of plastic materials, namely, Nylon-66 and Polyoxymethylene (Delrin. These materials have applications in automotives as engine seals, gaskets, fuel system seals and hoses, and so forth. Two types of the ethanol blended gasoline mixtures were used: (a gasoline containing 5% ethanol (E5, which is commercial form of gasoline available in India, and (b gasoline containing 10% ethanol (E10. The above materials were immersed in E5 and E10 for 500 hrs at 55°C. A set of eight different properties in E5 and E10 (visual inspection, weight change, volume change, tensile strength, percent elongation, flexural strength, impact strength, and hardness were measured after completion of 500 hrs and compared with reference specimens (specimens at 55°C without fuel and specimens at ambient conditions. Variation observed in different materials with respect to the above eight properties has been used to draw inference about the compatibility of these elastomeric/polymer materials with E10 fuel vis-à-vis E5 fuels. The data presented in this study is comparative in nature between the results of E10 and E5.

  13. Antiparasitic prodrug nifurtimox: revisiting its activation mechanism.

    Science.gov (United States)

    Cerecetto, Hugo; González, Mercedes

    2011-08-01

    EVALUATION OF: Hall BS, Bot C, Wilkinson SR. Nifurtimox activation by trypanosomal type I nitroreductases generates cytotoxic nitrile metabolites. J. Biol. Chem. 286, 13088-13095 (2011). The prodrug nifurtimox has been one of the pharmacologic alternatives to treat Chagas disease and currently forms part of a combinational therapy to treat West African trypanosomiasis. Despite this, nifurtimox's mechanism of action is only partially understood and has been related to induction of oxidative stress in the target cell. An alternative mechanism involving reductive activation by a eukaryotic type I nitroreductase has been described. Bloodstream form Trypanosoma brucei overexpressing enzymes, proposed to metabolize nifurtimox, were generated and only cells with elevated levels of the nitroreductase displayed altered susceptibility to the drug, implying that it has a key role in drug action. Reduction of nifurtimox by trypanosomal type I nitroreductases was shown to be insensitive to oxygen and yielded a product characterized by liquid chromatography/mass spectrometry as an unsaturated open chain nitrile. This nitrile inhibited both parasite and mammalian cell growth at equivalent concentrations, in marked contrast to the parental prodrug. These studies indicated that nifurtimox selectivity against T. brucei could be the result of the expression of a parasite-encoded type I nitroreductase.

  14. The band gap variation of a two dimensional binary locally resonant structure in thermal environment

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    Zhen Li

    2017-01-01

    Full Text Available In this study, the numerical investigation of thermal effect on band gap dynamical characteristic for a two-dimensional binary structure composed of aluminum plate periodically filled with nitrile rubber cylinder is presented. Initially, the band gap of the binary structure variation trend with increasing temperature is studied by taking the softening effect of thermal stress into account. A breakthrough is made which found the band gap being narrower and shifting to lower frequency in thermal environment. The complete band gap which in higher frequency is more sensitive to temperature that it disappears with temperature increasing. Then some new transformed models are created by changing the height of nitrile rubber cylinder from 1mm to 7mm. Simulations show that transformed model can produce a wider band gap (either flexure or complete band gap. A proper forbidden gap of elastic wave can be utilized in thermal environment although both flexure and complete band gaps become narrower with temperature. Besides that, there is a zero-frequency flat band appearing in the first flexure band, and it becomes broader with temperature increasing. The band gap width decreases trend in thermal environment, as well as the wider band gap induced by the transformed model with higher nitrile rubber cylinder is useful for the design and application of phononic crystal structures in thermal environment.

  15. Reactivity of Ruthenium Vinylidene Complexes Containing Indenyl/dppe Ligands and Unsaturated Bonds at Cd with Trimethylsilyl Azide

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    Chin-Pao Cheng

    2012-07-01

    Full Text Available This study presents a new reaction of cationic vinylidene complexes with Me3SiN3 (TMSN3, which yields N-coordinated nitrile complexes 3. Treatment of a ruthenium acetylide precursor containing indenyl and dppe ligands with a series of organic halides produced the corresponding vinylidene complexes 2 in good yield. Further reaction of 2 with TMSN3 at room temperature produced N-coordinated ruthenium nitrile complexes 3. Unlike the reaction of cyclopropenylruthenium complexes with TMSN3, which yielded different products depending on the substituent at Cγ, the vinylidene complexes containing unsaturated bonds at Cd yielded similar N-coordinated nitrile complexes. This transformation did not seemingly occur in the reaction of ruthenium vinylidene complexes containing Cp and PPh3 ligands with TMSN3. Deprotonation of these vinylidene complexes yielded cyclopropenyl or thermodynamic furylruthenium complexes, depending on the substitute at Cγ. Subsequent reactions of the cyclopropenyl or furylruthenium complexes with TMSN3 afforded different products.

  16. Zirconocene and Si-tethered diynes: a happy match directed toward organometallic chemistry and organic synthesis.

    Science.gov (United States)

    Zhang, Wen-Xiong; Zhang, Shaoguang; Xi, Zhenfeng

    2011-07-19

    Characterizing reactive organometallic intermediates is critical for understanding the mechanistic aspects of metal-mediated organic reactions. Moreover, the isolation of reactive organometallic intermediates can often result in the ability to design new synthetic methods. In this Account, we outline synthetic methods that we developed for a variety of diverse Zr/Si organo-bimetallic compounds and Si/N heteroatom-organic compounds through the detailed study of zirconacyclobutene-silacyclobutene fused compounds. Two basic components are involved in this chemistry. The first is the Si-tethered diyne, which owes its rich reactive palette to the combination of the Si-C bond and the C≡C triple bond. The second is the low-valent zirconocene species Cp(2)Zr(II), which has proven very useful in organic synthesis. The reaction of these two components affords the zirconacyclobutene-silacyclobutene fused compound, which is the key reactive Zr/Si organo-bimetallic intermediate discussed here. We discuss the three types of reactions that have been developed for the zirconacyclobutene-silacyclobutene fused intermediate. The reaction with nitriles (the C≡N triple bond) is introduced in the first section. In this one-pot reaction, up to four different components can be combined: the Si-tethered diyne can be reacted with three identical nitriles, with differing nitriles, or with a nitrile and other unsaturated organic substrates such as formamides, isocyanides, acid chlorides, aldehydes, carbodiimides, and azides. Several unexpected multiring, fused Zr/Si organo-bimetallic intermediates were isolated and characterized. A wide variety of N-heterocycles, such as 5-azaindole, pyrrole, and pyrroloazepine derivatives, were obtained. We then discuss the reaction with alkynes (the C≡C triple bond). A consecutive skeletal rearrangement, differing from that observed in the reactions with nitriles, takes place in this reaction. Finally, we discuss the reaction with the C═X substrates

  17. Electrophysiological Responses and Reproductive Behavior of Fall Webworm Moths (Hyphantria cunea Drury) are Influenced by Volatile Compounds from Its Mulberry Host (Morus alba L.).

    Science.gov (United States)

    Tang, Rui; Zhang, Feng; Zhang, Zhong-Ning

    2016-05-03

    Hyphantria cunea (Drury) is an invasive pest of Morus alba L. in China. β-ocimene and cis-2-penten-1-ol among eleven electro-physiologically active leaf volatiles from M. alba have been reported to influence captures of Hyphantria cunea moths when added into sex pheromone traps. This study further investigated influences of volatile types and their dosages on the electro-physiological responses in the antennae of male and female moths, as well as on mating and oviposition behaviors. Females were, regardless of dosages, more sensitive to β-ocimene and cis-2-penten-1-ol in electro-physiological response tests than males. For males, a dose response was detected, i.e., a dosage of 10 μg and 100 μg of either chemical stimulated higher electric response in their antennae than 1 μg. Moth pairs either exposed respectively to a herbivore-induced M. alba volatile blend (HIPV), to a mechanically-damaged M. alba volatile blend (MDV), to β-ocimene, to cis-2-penten-1-ol, or to pentane as a control showed that pairs exposed to β-ocimene most likely mated, followed by HIPV blends and least by the other volatiles or the control. In contrast, β-ocimene induced about 70% of the female oviposition behaviors and was nearly 4.5 times the oviposition rate than cis-2-penten-1-ol and 2 times than the control. However, none of the chemicals had any effect on the 48 h fecundity or on egg sizes. In conclusion, β-ocimene from mulberry plants alone could promote mating and oviposition in H. cunea at a dosage of 1 mg. The results indicate that reproductive behaviors of H. cunea moths can be enhanced through HIPV blends and β-ocimene induced by feeding of larvae. This contra phenomenon has revealed a different ecology in this moth during colonizing China as local pests would commonly be repelled by herbivore induced chemicals. These chemicals can be used for the development of biological control approaches such as being used together with sex pheromone traps.

  18. Electrophysiological Responses and Reproductive Behavior of Fall Webworm Moths (Hyphantria cunea Drury are Influenced by Volatile Compounds from Its Mulberry Host (Morus alba L.

    Directory of Open Access Journals (Sweden)

    Rui Tang

    2016-05-01

    Full Text Available Hyphantria cunea (Drury is an invasive pest of Morus alba L. in China. β-ocimene and cis-2-penten-1-ol among eleven electro-physiologically active leaf volatiles from M. alba have been reported to influence captures of Hyphantria cunea moths when added into sex pheromone traps. This study further investigated influences of volatile types and their dosages on the electro-physiological responses in the antennae of male and female moths, as well as on mating and oviposition behaviors. Females were, regardless of dosages, more sensitive to β-ocimene and cis-2-penten-1-ol in electro-physiological response tests than males. For males, a dose response was detected, i.e., a dosage of 10 μg and 100 μg of either chemical stimulated higher electric response in their antennae than 1 μg. Moth pairs either exposed respectively to a herbivore-induced M. alba volatile blend (HIPV, to a mechanically-damaged M. alba volatile blend (MDV, to β-ocimene, to cis-2-penten-1-ol, or to pentane as a control showed that pairs exposed to β-ocimene most likely mated, followed by HIPV blends and least by the other volatiles or the control. In contrast, β-ocimene induced about 70% of the female oviposition behaviors and was nearly 4.5 times the oviposition rate than cis-2-penten-1-ol and 2 times than the control. However, none of the chemicals had any effect on the 48 h fecundity or on egg sizes. In conclusion, β-ocimene from mulberry plants alone could promote mating and oviposition in H. cunea at a dosage of 1 mg. The results indicate that reproductive behaviors of H. cunea moths can be enhanced through HIPV blends and β-ocimene induced by feeding of larvae. This contra phenomenon has revealed a different ecology in this moth during colonizing China as local pests would commonly be repelled by herbivore induced chemicals. These chemicals can be used for the development of biological control approaches such as being used together with sex pheromone traps.

  19. Electrophysiological Responses and Reproductive Behavior of Fall Webworm Moths (Hyphantria cunea Drury) are Influenced by Volatile Compounds from Its Mulberry Host (Morus alba L.)

    Science.gov (United States)

    Tang, Rui; Zhang, Feng; Zhang, Zhong-Ning

    2016-01-01

    Hyphantria cunea (Drury) is an invasive pest of Morus alba L. in China. β-ocimene and cis-2-penten-1-ol among eleven electro-physiologically active leaf volatiles from M. alba have been reported to influence captures of Hyphantria cunea moths when added into sex pheromone traps. This study further investigated influences of volatile types and their dosages on the electro-physiological responses in the antennae of male and female moths, as well as on mating and oviposition behaviors. Females were, regardless of dosages, more sensitive to β-ocimene and cis-2-penten-1-ol in electro-physiological response tests than males. For males, a dose response was detected, i.e., a dosage of 10 μg and 100 μg of either chemical stimulated higher electric response in their antennae than 1 μg. Moth pairs either exposed respectively to a herbivore-induced M. alba volatile blend (HIPV), to a mechanically-damaged M. alba volatile blend (MDV), to β-ocimene, to cis-2-penten-1-ol, or to pentane as a control showed that pairs exposed to β-ocimene most likely mated, followed by HIPV blends and least by the other volatiles or the control. In contrast, β-ocimene induced about 70% of the female oviposition behaviors and was nearly 4.5 times the oviposition rate than cis-2-penten-1-ol and 2 times than the control. However, none of the chemicals had any effect on the 48 h fecundity or on egg sizes. In conclusion, β-ocimene from mulberry plants alone could promote mating and oviposition in H. cunea at a dosage of 1 mg. The results indicate that reproductive behaviors of H. cunea moths can be enhanced through HIPV blends and β-ocimene induced by feeding of larvae. This contra phenomenon has revealed a different ecology in this moth during colonizing China as local pests would commonly be repelled by herbivore induced chemicals. These chemicals can be used for the development of biological control approaches such as being used together with sex pheromone traps. PMID:27153095

  20. A Nicotiana attenuata cell wall invertase inhibitor (NaCWII) reduces growth and increases secondary metabolite biosynthesis in herbivore-attacked plants.

    Science.gov (United States)

    Ferrieri, Abigail P; Arce, Carla C M; Machado, Ricardo A R; Meza-Canales, Ivan D; Lima, Eraldo; Baldwin, Ian T; Erb, Matthias

    2015-10-01

    Plant invertases are sucrolytic enzymes that are essential for the regulation of carbohydrate metabolism and source-sink relationships. While their activity has been well documented during abiotic and biotic stresses, the role of proteinaceous invertase inhibitors in regulating these changes is unknown. Here, we identify a putative Nicotiana attenuata cell wall invertase inhibitor (NaCWII) which is strongly up-regulated in a jasmonate (JA)-dependent manner following simulated attack by the specialist herbivore Manduca sexta. To understand the role of NaCWII in planta, we silenced its expression by RNA interference and measured changes in primary and secondary metabolism and plant growth following simulated herbivory. NaCWII-silenced plants displayed a stronger depletion of carbohydrates and a reduced capacity to increase secondary metabolite pools relative to their empty vector control counterparts. This coincided with the attenuation of herbivore-induced CWI inhibition and growth suppression characteristic of wild-type plants. Together our findings suggest that NaCWII may act as a regulatory switch located downstream of JA accumulation which fine-tunes the plant's balance between growth and defense metabolism under herbivore attack. Although carbohydrates are not typically viewed as key factors in plant growth and defense, our study shows that interfering with their catabolism strongly influences plant responses to herbivory. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  1. Foliar methyl salicylate emissions indicate prolonged aphid infestation on silver birch and black alder.

    Science.gov (United States)

    Blande, James D; Korjus, Minna; Holopainen, Jarmo K

    2010-03-01

    It is well documented that when plants are damaged by insects they respond by emitting a range of volatile organic compounds (VOCs). While there have been numerous reports concerning VOCs induced by chewing herbivores, there are relatively few studies detailing the VOCs induced by aphid feeding. The effects of aphid feeding on VOCs emitted by boreal forest trees have been particularly neglected. Herbivore-induced VOCs have relevance to direct and indirect plant defence and atmospheric chemistry. In this study, we analysed the VOCs emitted by Betula pendula (Roth) and Alnus glutinosa (L.) (Gaertn.) infested by specialist aphid species under laboratory conditions. We also complemented this by collecting VOCs from leaf beetle-damaged saplings under field conditions. In addition to induction of some inducible terpenes, we detected substantial aphid-induced emissions of methyl salicylate (MeSA) in both B. pendula and A. glutinosa. MeSA emission intensity depended on the length of aphid infestation. Feeding by beetles induced emission of (E)-DMNT in both tree species and (E)-beta-ocimene in A. glutinosa but had no effect on MeSA emissions. MeSA has been shown to have aphid-repellent qualities and has been shown recently to have impact on formation of secondary organic aerosols in the atmosphere. We discuss our results in relation to these two phenomena.

  2. Differing Behavioural Responses of Bemisia tabaci MEAM1 and MED to Cabbage Damaged by Conspecifics and Heterospecifics.

    Science.gov (United States)

    Kong, Hailong; Zeng, Yang; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Jiao, Xiaoguo; Xu, Baoyun; Zhang, Youjun

    2016-10-12

    The whitefly Bemisia tabaci is a serious pest with an extensive host range. Previous research has shown that B. tabaci is a species complex with many cryptic species or biotypes and that the two most important species are MEAM1 (Middle East-Minor Asia 1) and MED (Mediterranean genetic group). MEAM1 and MED are known to differ in their preference for cabbage, Brassica oleracea, as a host plant, however, the mechanism underlying this preference is unknown. In the current study, a host choice experiment showed that MED prefers to settle and oviposit on undamaged cabbage plants rather than MED-damaged cabbage plants. However, MEAM1 prefers MED-damaged cabbage plants to undamaged plants and does not exhibit a significant preference for undamaged or MEAM1-damaged cabbage plants. On the basis of gas chromatography-mass spectrometry (GC-MS) analysis, the following volatiles were released in larger quantities from Q-damaged cabbage plants than from undamaged plants: 2-ethyl-1-hexanol, benzenemethanol, (E)-2-decenol, benzaldehyde, nonanal, acetic acid geraniol ester, 4-hydroxy-4-methyl-2-pentanone, decane, and α-longipinene. Only one volatile, 4-hydroxy-4-methyl-2-pentanone, was released in greater quantities from MEAM1-damaged cabbage plants than from undamaged plants. Our results suggest that differences in herbivore-induced host volatile release may help explain the differences between the preference of B. tabaci MEAM1 and MED for cabbage as a host.

  3. Plant defences limit herbivore population growth by changing predator-prey interactions.

    Science.gov (United States)

    Kersch-Becker, Mônica F; Kessler, André; Thaler, Jennifer S

    2017-09-13

    Plant quality and predators are important factors affecting herbivore population growth, but how they interact to regulate herbivore populations is not well understood. We manipulated jasmonate-induced plant resistance, exposure to the natural predator community and herbivore density to test how these factors jointly and independently affect herbivore population growth. On low-resistance plants, the predator community was diverse and abundant, promoting high predator consumption rates. On high-resistance plants, the predator community was less diverse and abundant, resulting in low predator consumption rate. Plant resistance only directly regulated aphid population growth on predator-excluded plants. When predators were present, plant resistance indirectly regulated herbivore population growth by changing the impact of predators on the herbivorous prey. A possible mechanism for the interaction between plant resistance and predation is that methyl salicylate, a herbivore-induced plant volatile attractive to predators, was more strongly induced in low-resistance plants. Increased plant resistance reduced predator attractant lures, preventing predators from locating their prey. Low-resistance plants may regulate herbivore populations via predators by providing reliable information on prey availability and increasing the effectiveness of predators. © 2017 The Author(s).

  4. Genetic Variation of the Host Plant Species Matters for Interactions with Above- and Belowground Herbivores

    Directory of Open Access Journals (Sweden)

    Dinesh Kafle

    2014-08-01

    Full Text Available Plants are challenged by both above- and belowground herbivores which may indirectly interact with each other via herbivore-induced changes in plant traits; however, little is known about how genetic variation of the host plant shapes such interactions. We used two genotypes (M4 and E9 of Solanum dulcamara (Solanaceae with or without previous experience of aboveground herbivory by Spodoptera exigua (Noctuidae to quantify its effects on subsequent root herbivory by Agriotes spp. (Elateridae. In the genotype M4, due to the aboveground herbivory, shoot and root biomass was significantly decreased, roots had a lower C/N ratio and contained significantly higher levels of proteins, while the genotype E9 was not affected. However, aboveground herbivory had no effects on weight gain or mortality of the belowground herbivores. Root herbivory by Agriotes increased the nitrogen concentration in the roots of M4 plants leading to a higher weight gain of conspecific larvae. Also, in feeding bioassays, Agriotes larvae tended to prefer roots of M4 over E9, irrespective of the aboveground herbivore treatment. Fourier-Transform Infrared Spectroscopy (FT-IR documented differences in metabolic profiles of the two plant genotypes and of the roots of M4 plants after aboveground herbivory. Together, these results demonstrate that previous aboveground herbivory can have genotype-specific effects on quantitative and qualitative root traits. This may have consequences for belowground interactions, although generalist root herbivores might not be affected when the root biomass offered is still sufficient for growth and survival.

  5. Jasmonate-dependent depletion of soluble sugars compromises plant resistance to Manduca sexta.

    Science.gov (United States)

    Machado, Ricardo A R; Arce, Carla C M; Ferrieri, Abigail P; Baldwin, Ian T; Erb, Matthias

    2015-07-01

    Jasmonates regulate plant secondary metabolism and herbivore resistance. How they influence primary metabolites and how this may affect herbivore growth and performance are not well understood. We profiled sugars and starch of jasmonate biosynthesis-deficient and jasmonate-insensitive Nicotiana attenuata plants and manipulated leaf carbohydrates through genetic engineering and in vitro complementation to assess how jasmonate-dependent sugar accumulation affects the growth of Manduca sexta caterpillars. We found that jasmonates reduce the constitutive and herbivore-induced concentration of glucose and fructose in the leaves across different developmental stages. Diurnal, jasmonate-dependent inhibition of invertase activity was identified as a likely mechanism for this phenomenon. Contrary to our expectation, both in planta and in vitro approaches showed that the lower sugar concentrations led to increased M. sexta growth. As a consequence, jasmonate-dependent depletion of sugars rendered N. attenuata plants more susceptible to M. sexta attack. In conclusion, jasmonates are important regulators of leaf carbohydrate accumulation and this determines herbivore growth. Jasmonate-dependent resistance is reduced rather than enhanced through the suppression of glucose and fructose concentrations, which may contribute to the evolution of divergent resistance strategies of plants in nature. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  6. Plant defense against herbivorous pests: exploiting resistance and tolerance traits for sustainable crop protection

    Directory of Open Access Journals (Sweden)

    Carolyn Mitchell

    2016-07-01

    Full Text Available Interactions between plants and insect herbivores are important determinants of plant productivity in managed and natural vegetation. In response to attack, plants have evolved a range of defenses to reduce the threat of injury and loss of productivity. Crop losses from damage caused by arthropod pests can exceed 15% annually. Crop domestication and selection for improved yield and quality can alter the defensive capability of the crop, increasing reliance on artificial crop protection. Sustainable agriculture, however, depends on reduced chemical inputs. There is an urgent need, therefore, to identify plant defensive traits for crop improvement. Plant defense can be divided into resistance and tolerance strategies. Plant traits that confer herbivore resistance typically prevent or reduce herbivore damage through expression of traits that deter pests from settling, attaching to surfaces, feeding and reproducing, or that reduce palatability. Plant tolerance of herbivory involves expression of traits that limit the negative impact of herbivore damage on productivity and yield. Identifying the defensive traits expressed by plants to deter herbivores or limit herbivore damage, and understanding the underlying defense mechanisms, is crucial for crop scientists to exploit plant defensive traits in crop breeding. In this review, we assess the traits and mechanisms underpinning herbivore resistance and tolerance, and conclude that physical defense traits, plant vigor and herbivore-induced plant volatiles show considerable utility in pest control, along with mixed species crops. We highlight emerging approaches for accelerating the identification of plant defensive traits and facilitating their deployment to improve the future sustainability of crop protection.

  7. Nerolidol: A Sesquiterpene Alcohol with Multi-Faceted Pharmacological and Biological Activities

    Directory of Open Access Journals (Sweden)

    Weng-Keong Chan

    2016-04-01

    Full Text Available Nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol is a naturally occurring sesquiterpene alcohol that is present in various plants with a floral odor. It is synthesized as an intermediate in the production of (3E-4,8-dimethy-1,3,7-nonatriene (DMNT, a herbivore-induced volatile that protects plants from herbivore damage. Chemically, nerolidol exists in two geometric isomers, a trans and a cis form. The usage of nerolidol is widespread across different industries. It has been widely used in cosmetics (e.g., shampoos and perfumes and in non-cosmetic products (e.g., detergents and cleansers. In fact, U.S. Food and Drug Administration (FDA has also permitted the use of nerolidol as a food flavoring agent. The fact that nerolidol is a common ingredient in many products has attracted researchers to explore more medicinal properties of nerolidol that may exert beneficial effect on human health. Therefore, the aim of this review is to compile and consolidate the data on the various pharmacological and biological activities displayed by nerolidol. Furthermore, this review also includes pharmacokinetic and toxicological studies of nerolidol. In summary, the various pharmacological and biological activities demonstrated in this review highlight the prospects of nerolidol as a promising chemical or drug candidate in the field of agriculture and medicine.

  8. The neural bases of host plant selection in a Neuroecology framework

    Directory of Open Access Journals (Sweden)

    Carolina E Reisenman

    2015-08-01

    Full Text Available Understanding how animals make use of environmental information to guide behavior is a fundamental problem in the field of neuroscience. Similarly, the field of ecology seeks to understand the role of behavior in shaping interactions between organisms at various levels of organization, including population-, community- and even ecosystem-level scales. Together, the newly emerged field of Neuroecology seeks to unravel this fundamental question by studying both the function of neurons at many levels of the sensory pathway and the interactions between organisms and their natural environment. The interactions between herbivorous insects and their host plants are ideal examples of Neuroecology given the strong ecological and evolutionary forces and the underlying physiological and behavioral mechanisms that shaped these interactions. In this review we focus on an exemplary herbivorous insect within the Lepidoptera, the giant sphinx moth Manduca sexta, as much is known about the natural behaviors related to hostplant selection and the involved neurons at several level of the sensory pathway. We also discuss how herbivore-induced plant odorants and secondary metabolites in floral nectar in turn can affect moth behavior, and the underlying neural mechanisms.

  9. Root traits predict decomposition across a landscape-scale grazing experiment.

    Science.gov (United States)

    Smith, Stuart W; Woodin, Sarah J; Pakeman, Robin J; Johnson, David; van der Wal, René

    2014-08-01

    Root litter is the dominant soil carbon and nutrient input in many ecosystems, yet few studies have considered how root decomposition is regulated at the landscape scale and how this is mediated by land-use management practices. Large herbivores can potentially influence below-ground decomposition through changes in soil microclimate (temperature and moisture) and changes in plant species composition (root traits). To investigate such herbivore-induced changes, we quantified annual root decomposition of upland grassland species in situ across a landscape-scale livestock grazing experiment, in a common-garden experiment and in laboratory microcosms evaluating the influence of key root traits on decomposition. Livestock grazing increased soil temperatures, but this did not affect root decomposition. Grazing had no effect on soil moisture, but wetter soils retarded root decomposition. Species-specific decomposition rates were similar across all grazing treatments, and species differences were maintained in the common-garden experiment, suggesting an overriding importance of litter type. Supporting this, in microcosms, roots with lower specific root area (m(2) g(-1)) or those with higher phosphorus concentrations decomposed faster. Our results suggest that large herbivores alter below-ground carbon and nitrogen dynamics more through their effects on plant species composition and associated root traits than through effects on the soil microclimate. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  10. A tritrophic signal that attracts parasitoids to host-damaged plants withstands disruption by non-host herbivores

    Directory of Open Access Journals (Sweden)

    Turlings Ted CJ

    2010-11-01

    Full Text Available Abstract Background Volatiles emitted by herbivore-infested plants are highly attractive to parasitoids and therefore have been proposed to be part of an indirect plant defense strategy. However, this proposed function of the plant-provided signals remains controversial, and it is unclear how specific and reliable the signals are under natural conditions with simultaneous feeding by multiple herbivores. Phloem feeders in particular are assumed to interfere with plant defense responses. Therefore, we investigated how attack by the piercing-sucking cicadellid Euscelidius variegatus influences signaling by maize plants in response to the chewing herbivore Spodoptera littoralis. Results The parasitoid Cotesia marginiventris strongly preferred volatiles of plants infested with its host S. littoralis. Overall, the volatile emissions induced by S. littoralis and E. variegatus were similar, but higher levels of certain wound-released compounds may have allowed the wasps to specifically recognize plants infested by hosts. Expression levels of defense marker genes and further behavioral bioassays with the parasitoid showed that neither the physiological defense responses nor the attractiveness of S. littoralis infested plants were altered by simultaneous E. variegatus attack. Conclusions Our findings imply that plant defense responses to herbivory can be more robust than generally assumed and that ensuing volatiles convey specific information about the type of herbivore that is attacking a plant, even in complex situations with multiple herbivores. Hence, the results of this study support the notion that herbivore-induced plant volatiles may be part of a plant's indirect defense stratagem.

  11. Caterpillars of Euphydryas aurinia (Lepidoptera: Nymphalidae) feeding on Succisa pratensis leaves induce large foliar emissions of methanol.

    Science.gov (United States)

    Peñuelas, Josep; Filella, Iolanda; Stefanescu, Constantí; Llusià, Joan

    2005-09-01

    A major new discovery made in the last decade is that plants commonly emit large amounts and varieties of volatiles after damage inflicted by herbivores, and not merely from the site of injury. However, analytical methods for measuring herbivore-induced volatiles do not usually monitor the whole range of these compounds and are complicated by the transient nature of their formation and by their chemical instability. Here we present the results of using a fast and highly sensitive proton transfer reaction-mass spectrometry (PTR-MS) technique that allows simultaneous on-line monitoring of leaf volatiles in the pptv (pmol mol(-1)) range. The resulting on-line mass scans revealed that Euphydryas aurinia caterpillars feeding on Succisa pratensis leaves induced emissions of huge amounts of methanol--a biogeochemically active compound and a significant component of the volatile organic carbon found in the atmosphere--and other immediate, late and systemic volatile blends (including monoterpenes, sesquiterpenes and lipoxygenase-derived volatile compounds). In addition to influencing neighboring plants, as well as herbivores and their predators and parasitoids, these large emissions might affect atmospheric chemistry and physics if they are found to be generalized in other plant species.

  12. Terpenoids in plant and arbuscular mycorrhiza-reinforced defence against herbivorous insects.

    Science.gov (United States)

    Sharma, Esha; Anand, Garima; Kapoor, Rupam

    2017-03-01

    Plants, though sessile, employ various strategies to defend themselves against herbivorous insects and convey signals of an impending herbivore attack to other plant(s). Strategies include the production of volatiles that include terpenoids and the formation of symbiotic associations with fungi, such as arbuscular mycorrhiza (AM). This constitutes a two-pronged above-ground/below-ground attack-defence strategy against insect herbivores. Terpenoids represent an important constituent of herbivore-induced plant volatiles that deter herbivores and/or attract their predators. Terpenoids serve as airborne signals that can induce defence responses in systemic undamaged parts of the plant and also prime defence responses in neighbouring plants. Colonization of roots by AM fungi is known to influence secondary metabolism in plants; this includes alteration of the concentration and composition of terpenoids, which can boost both direct and indirect plant defence against herbivorous insects. Enhanced nutrient uptake facilitated by AM, changes in plant morphology and physiology and increased transcription levels of certain genes involved in the terpenoid biosynthesis pathway result in alterations in plant terpenoid profiles. The common mycorrhizal networks of external hyphae have added a dimension to the two-pronged plant defence strategy. These act as conduits to transfer defence signals and terpenoids. Improved understanding of the roles of terpenoids in plant and AM defences against herbivory and of interplant signalling in natural communities has significant implications for sustainable management of pests in agricultural ecosystems.

  13. The transcriptional response of hybrid poplar (Populus trichocarpa x P. deltoides) to infection by Melampsora medusae leaf rust involves induction of flavonoid pathway genes leading to the accumulation of proanthocyanidins.

    Science.gov (United States)

    Miranda, Manoela; Ralph, Steven G; Mellway, Robin; White, Rick; Heath, Michele C; Bohlmann, Jörg; Constabel, C Peter

    2007-07-01

    The transcriptional response of hybrid poplar (Populus trichocarpa x P. deltoides) to poplar leaf rust (Melampsora medusae) infection was studied using the Populus 15.5K cDNA microarray. Pronounced changes in the transcriptome were observed, with approximately 20% of genes on the array showing either induction or repression of transcription within the 9-day infection timecourse. A small number of pathogen-defense genes encoding PR-1, chitinases, and other pathogenesis-related proteins were consistently upregulated throughout the experimental period, but most genes were affected only at individual timepoints. The largest number of changes in gene expression was observed late in the infection at 6 to 9 days postinoculation (dpi). At these timepoints, genes encoding enzymes required for proanthocyanidin (condensed tannin) synthesis were upregulated dramatically. Phytochemical analysis confirmed that, late in the infection, proanthocyanidin levels increased in infected leaves. Strongly M. medusae-repressed genes at 9 dpi included previously characterized wound- and herbivore-induced defense genes, which suggests antagonism between the tree responses to insect feeding and M. medusae infection. In this highly compatible plant-pathogen interaction, we postulate that the biotrophic pathogen evades detection and suppresses early host responses.

  14. Similar metabolic changes induced by HIPVs exposure as herbivore in Ammopiptanthus mongolicus.

    Science.gov (United States)

    Sun, Jingru; Zhang, Xiao; Cao, Chuanjian; Mei, Xindi; Wang, Ningning; Yan, Suli; Zong, Shixiang; Luo, Youqing; Yang, Haijun; Shen, Yingbai

    2014-01-01

    Herbivore-induced plant volatiles (HIPVs) are important compounds to prim neighboring undamaged plants; however, the mechanism for this priming process remains unclear. To reveal metabolic changes in plants exposed to HIPVs, metabolism of leaves and roots of Ammopiptanthus mongolicus seedlings exposed to HIPVs released from conspecific plants infested with larvae of Orgyia ericae were analyzed together with control and infested seedlings using nuclear magnetic resonance (NMR)-based metabolic technology and multi variate data analysis. Results presented showed that HIPVs exposure led to similar but specific metabolic changes compared with those induced by infestation in both leaves and roots. Furthermore, both HIPVs exposure and herbivore attack resulted in metabolic changes involving a series of primary and secondary metabolites in both leaves and roots. Taken together, these results suggested that priming of yet-damaged plants may be achieved by reconfiguring metabolic pathways in leaves and roots to make similar concentrations for all metabolites as those in seedlings infested. Therefore, we propose that improved readiness of defense induction of primed plants toward subsequent herbivore attack may be based on the similar metabolic profiling induced by HIPVs exposure as those caused by herbivore.

  15. Similar metabolic changes induced by HIPVs exposure as herbivore in Ammopiptanthus mongolicus.

    Directory of Open Access Journals (Sweden)

    Jingru Sun

    Full Text Available Herbivore-induced plant volatiles (HIPVs are important compounds to prim neighboring undamaged plants; however, the mechanism for this priming process remains unclear. To reveal metabolic changes in plants exposed to HIPVs, metabolism of leaves and roots of Ammopiptanthus mongolicus seedlings exposed to HIPVs released from conspecific plants infested with larvae of Orgyia ericae were analyzed together with control and infested seedlings using nuclear magnetic resonance (NMR-based metabolic technology and multi variate data analysis. Results presented showed that HIPVs exposure led to similar but specific metabolic changes compared with those induced by infestation in both leaves and roots. Furthermore, both HIPVs exposure and herbivore attack resulted in metabolic changes involving a series of primary and secondary metabolites in both leaves and roots. Taken together, these results suggested that priming of yet-damaged plants may be achieved by reconfiguring metabolic pathways in leaves and roots to make similar concentrations for all metabolites as those in seedlings infested. Therefore, we propose that improved readiness of defense induction of primed plants toward subsequent herbivore attack may be based on the similar metabolic profiling induced by HIPVs exposure as those caused by herbivore.

  16. Leaf herbivory imposes fitness costs mediated by hummingbird and insect pollinators.

    Directory of Open Access Journals (Sweden)

    Alexander Chautá

    Full Text Available Plant responses induced by herbivore damage can provide fitness benefits, but can also have important costs due to altered interactions with mutualist pollinators. We examined the effects of plant responses to herbivory in a hummingbird-pollinated distylous shrub, Palicourea angustifolia. Through a series of field experiments we investigated whether damage from foliar herbivores leads to a reduction in fruit set, influences floral visitation, or alters floral traits that may influence pollinator preference or pollinator efficiency. Foliar herbivory by a generalist grasshopper led to reduced fruit set in branches that were directly damaged as well as in adjacent undamaged branches on the same plant. Furthermore, herbivory resulted in reduced floral visitation from two common hummingbird species and two bee species. An investigation into the potential mechanisms behind reduced floral visitation in induced plants showed that foliar herbivore damage resulted in shorter styles and lower nectar volumes. This reduction in style length could reduce pollen deposition between different floral morphs that is required for optimal pollination in a distylous plant. We did not detect any differences in the volatile blends released by damaged and undamaged branches, suggesting that foliar herbivore-induced changes in floral morphology and rewards, and not volatile blends, are the primary mechanism mediating changes in visitation. Our results provide novel mechanisms for how plant responses induced by foliar herbivores can lead to ecological costs.

  17. Herbivory-induced jasmonates constrain plant sugar accumulation and growth by antagonizing gibberellin signaling and not by promoting secondary metabolite production.

    Science.gov (United States)

    Machado, Ricardo A R; Baldwin, Ian T; Erb, Matthias

    2017-07-01

    Plants respond to herbivory by reconfiguring hormonal networks, increasing secondary metabolite production and decreasing growth. Furthermore, some plants display a decrease in leaf energy reserves in the form of soluble sugars and starch, leading to the hypothesis that herbivory-induced secondary metabolite production and growth reduction may be linked through a carbohydrate-based resource trade-off. In order to test the above hypothesis, we measured leaf carbohydrates and plant growth in seven genetically engineered Nicotiana attenuata genotypes that are deficient in one or several major herbivore-induced, jasmonate-dependent defensive secondary metabolites and proteins. Furthermore, we manipulated gibberellin and jasmonate signaling, and quantified the impact of these phytohormones on secondary metabolite production, sugar accumulation and growth. Simulated herbivore attack by Manduca sexta specifically reduced leaf sugar concentrations and growth in a jasmonate-dependent manner. These effects were similar or even stronger in defenseless genotypes with intact jasmonate signaling. Gibberellin complementation rescued carbohydrate accumulation and growth in induced plants without impairing the induction of defensive secondary metabolites. These results are consistent with a hormonal antagonism model rather than a resource-cost model to explain the negative relationship between herbivory-induced defenses, leaf energy reserves and growth. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  18. The Transcription Factor OsWRKY45 Negatively Modulates the Resistance of Rice to the Brown Planthopper Nilaparvata lugens

    Directory of Open Access Journals (Sweden)

    Jiayi Huangfu

    2016-05-01

    Full Text Available WRKY transcription factors play a central role not only in plant growth and development but also in plant stress responses. However, the role of WRKY transcription factors in herbivore-induced plant defenses and their underlying mechanisms, especially in rice, remains largely unclear. Here, we cloned a rice WRKY gene OsWRKY45, whose expression was induced by mechanical wounding, by infestation of the brown planthopper (BPH, Nilaparvata lugens and by treatment with jasmonic acid (JA or salicylic acid (SA. The antisense expression of OsWRKY45 (as-wrky enhanced BPH-induced levels of H2O2 and ethylene, reduced feeding and oviposition preference as well as the survival rate of BPH, and delayed the development of BPH nymphs. Consistently, lower population densities of BPH on as-wrky lines, compared to those on wild-type (WT plants, were observed in field experiments. On the other hand, as-wrky lines in the field had lower susceptibility to sheath blight (caused by Rhizoctonia solani but higher susceptibility to rice blast (caused by Magnaporthe oryzae than did WT plants. These findings suggest that OsWRKY45 plays important but contrasting roles in regulating the resistance of rice to pathogens and herbivores, and attention should be paid if OsWRKY45 is used to develop disease or herbivore-resistant rice.

  19. Transport of a solvent mixture across two glove materials when applied in a paint matrix.

    Science.gov (United States)

    Tran, Jackelin Q; Ceballos, Diana M; Dills, Russell L; Yost, Michael G; Morgan, Michael S

    2012-07-01

    The transport of mixed paint solvents through natural rubber latex (4 mil) and nitrile rubber (5 mil) gloves was evaluated after spray application of the paint formulation directly on the glove surface. Glove materials and thicknesses were those selected by the majority of spray painters in the local automobile repair industry. A flat panel containing glove specimens mounted in multiple permeation cells permitted evaporation of solvents from the applied paint and incorporated a solid sorbent receiving medium for measuring glove membrane transport. The panel was sprayed in a paint booth to simulate use conditions. Charcoal cloth under the glove adsorbed transported solvents, which were quantified by gas chromatography. For each solvent component, results were expressed as mass transported through the glove relative to the mass applied, per unit area, during 30 min after spray application. The paint formulation contained ketones, acetates, and aromatics. Natural rubber latex allowed 6-10 times the transport of solvents relative to nitrile rubber for all eight solvent components: methyl ethyl ketone, toluene, styrene, ethyl benzene, xylene isomers, and 2-heptanone. m-Xylene showed the largest difference in transport between the two glove materials. This solvent also had the highest transport for each material. The results indicate that nitrile rubber gloves offer somewhat greater chemical resistance to all eight solvents studied compared with natural rubber latex gloves, regardless of the chemical properties of the individual solvent components. However, it must be emphasized that neither of the glove materials, in the thicknesses used in this study, provide adequate protection when exposed by direct spray painting. Simulation of realistic spray conditions may offer a source of useful information on the performance of chemical protective gloves because it accounts for solvent evaporation and the effect of paint polymerization after application on glove transport.

  20. Understanding factors that influence protective glove use among automotive spray painters.

    Science.gov (United States)

    Ceballos, Diana; Reeb-Whitaker, Carolyn; Glazer, Patricia; Murphy-Robinson, Helen; Yost, Michael

    2014-01-01

    Dermal contact with isocyanate-based coatings may lead to systemic respiratory sensitization. The most common isocyanates found in sprayed automotive coatings are monomeric and oligomeric 1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Most spray painters use thin (4-5 mil) latex gloves that are not effective at preventing dermal exposures when spraying isocyanate paints. Personal interviews with collision repair industry personnel and focus groups with spray painters were held to characterize risk awareness, to examine perceptions and challenges concerning protective glove use and selection, and to generate ideas for protective glove use interventions. The most popular gloves among spray painters were thin (4-5 mil) and thick (14 mil) latex. We found that medium to thick (6-8 mil) nitrile were not always perceived as comfortable and were expected to be more expensive than thin (4-5 mil) latex gloves. Of concern is the user's difficulty in distinguishing between nitrile and latex gloves; latex gloves are now sold in different colors including blue, which has traditionally been associated with nitrile gloves. Even though spray painters were familiar with the health hazards related to working with isocyanate paints, most were not always aware that dermal exposure to isocyanates could contribute to the development of occupational asthma. There is a need for more research to identify dermal materials that are protective against sprayed automotive coatings. Automotive spray painters and their employers need to be educated in the selection and use of protective gloves, specifically on attributes such as glove material, color, and thickness.

  1. Crystal structure and electrochemical properties of [Ni(bztmpen)(CH3CN)](BF4)2 {bztmpen is N-benzyl-N,N',N'-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine}.

    Science.gov (United States)

    Chen, Lin; Ren, Gan; Guo, Yakun; Sang, Ge

    2017-06-01

    The mononuclear nickel title complex (acetonitrile-κN){N-benzyl-N,N',N'-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine}-nickel(II) bis-(tetra-fluor-ido-borate), [Ni(C30H35N5)(CH3CN)](BF4)2, was prepared from the reaction of Ni(BF4)2·6H2O with N-benzyl-N,N',N'-tris-[(6-methyl-pyridin-2-yl)meth-yl]ethane-1,2-di-amine (bztmpen) in aceto-nitrile at room temperature. With an open site occupied by the aceto-nitrile mol-ecule, the nickel(II) atom is chelated by five N-atom sites from the ligand and one N atom from the ligand, showing an overall octa-hedral coordination environment. Compared with analogues where the 6-methyl substituent is absent, the bond length around the Ni2+ cation are evidently longer. Upon reductive dissociation of the acetro-nitrile mol-ecule, the title complex has an open site for a catalytic reaction. The title complex has two redox couples at -1.50 and -1.80 V (versus Fc+/0) based on nickel. The F atoms of the two BF4- counter-anions are split into two groups and the occupancy ratios refined to 0.611 (18):0.389 (18) and 0.71 (2):0.29 (2).

  2. Understanding Factors that Influence Protective Glove Use among Automotive Spray Painters

    Science.gov (United States)

    Ceballos, Diana; Reeb-Whitaker, Carolyn; Glazer, Patricia; Murphy-Robinson, Helen; Yost, Michael

    2017-01-01

    Dermal contact with isocyanate-based coatings may lead to systemic respiratory sensitization. The most common isocyanates found in sprayed automotive coatings are monomeric and oligomeric 1,6-hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Most spray painters use thin (4–5 mil) latex gloves that are not effective at preventing dermal exposures when spraying isocyanate paints. Personal interviews with collision repair industry personnel and focus groups with spray painters were held to characterize risk awareness, to examine perceptions and challenges concerning protective glove use and selection, and to generate ideas for protective glove use interventions. The most popular gloves among spray painters were thin (4–5 mil) and thick (14 mil) latex. We found that medium to thick (6–8 mil) nitrile were not always perceived as comfortable and were expected to be more expensive than thin (4–5 mil) latex gloves. Of concern is the users’ difficulty to distinguish between nitrile and latex gloves; latex gloves are now sold in different colors including blue, which has traditionally been associated with nitrile gloves. Even though spray painters were familiar with the health hazards related to working with isocyanate paints; most were not always aware that dermal exposure to isocyanates could contribute to the development of occupational asthma. There is a need for more research to identify dermal materials that are protective against sprayed automotive coatings. Automotive spray painters and their employers need to be educated in the selection and use of protective gloves, specifically on attributes such as glove material, color, and thickness. PMID:24215135

  3. Characterization of nanoclays dispersion in NBR nanocomposites by X-ray diffractograms;Caracterizacao da dispersao de nanoargilas em nanocompositos de NBR por difratografias de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Fabiula D.B.; Scuracchio, Carlos H.; Mantovani, Gerson L., E-mail: fabiulasousa@gmail.co [Universidade Federal do ABC (CECS/UFABC), Santo Andre, SP (Brazil). Centro de Engenharia Modelagem e Ciencias Sociais Aplicadas

    2009-07-01

    The main objective of this work is the study of nanoclays dispersion in NBR nanocomposites by X-ray diffraction. Nitrile rubbers NBR 3330 and NBR 3350 were used, both with 33%wt of acrylonitrile and with different Mooney viscosity. The nanoclays were bentonite, organically modified montmorillonite (Cloisite 30B{sup R}) and sodic montmorillonite. The results showed that the intercalation state of the filler had influence of both, the type of treatment at which clay was submitted and the molar mass of the polymer. (author)

  4. Magnetron reactively sputtered Ti-DLC coatings on HNBR rubber: The influence of substrate bias

    OpenAIRE

    Bui, X.L.; Pei, Y.T.; De Hosson, J. Th. M.

    2008-01-01

    In this study, Ti-containing diamond-like carbon (Ti-DLC) coatings have been deposited on HNBR (hydrogenated nitrile butadiene) rubber and also on Si wafer as reference via unbalanced magnetroli reactive sputtering from a Ti target in C2H2/Ar plasma. The deposition rates of coatings on rubber and Si wafer were about the same. Columnar structures resulting from a rough interface were often observed in the coatings deposited on rubbers. Only at a high bias voltage of -300 V the coating on HNBR ...

  5. On the friction and sliding wear of rubber/layered silicate nanocomposites

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The dry sliding and friction behaviors of organoclay modified hydrogenated nitrile (HNBR and ethylene/propylene/diene (EPDM rubbers were studied using a pin (steel-on-plate(rubber sheet test configuration. It was found that the organoclay modification may improve or deteriorate the resistance to wear of rubbers. The resistance to wear was adversely affected by pronounced intercalation/exfoliation and two-dimensional alignment of the clay layers (i.e. normal to the moving pin. This result is in analogy with the directional dependence of the wear performance of fiber-reinforced composite laminates.

  6. Development of an Integrated, Lightweight Combat Boot. Phase 1

    Science.gov (United States)

    1988-05-01

    Outsole 10 8. Increased Foot Health 10 III. Technical Objectives Not Met 10 IV. Production Trade-Cffs 11 I. Kevlar/PBI Quarter and Gusset 11 2. Chemical...Agent Resistant Bootie 11 3. Polyurethane/Nitrile Rubber Outsole 11 4. Puncture Resistant Insole 11 V. Future Design Changes 12 I. Boot Tread and Toe...375 Puncture resistant insole * 79 101 (as HotWeather) Tacks, nails and staples 0 7 Shank 6 19 Outsole and heel 284 400 Other 52 29 Total 733 931

  7. Study on similar model of high pressure water jet impacting coal rock

    Science.gov (United States)

    Liu, Jialiang; Wang, Mengjin; Zhang, Di

    2017-08-01

    Based on the similarity theory and dimensional analysis, the similarity criterion of the coal rock mechanical parameters were deduced. The similar materials were mainly built by the cement, sand, nitrile rubber powder and polystyrene, by controlling the water-cement ratio, cement-sand ratio, curing time and additives volume ratio. The intervals of the factors were obtained by carrying out series of material compression tests. By comparing the basic mechanical parameters such as the bulk density, compressive strength, Poisson ratio and elastic modulus between the coal rock prototype and similar materials, the optimal producing proposal of the coal rock similar materials was generated based on the orthogonal design tests finally.

  8. Efficient SN2 fluorination of primary and secondary alkyl bromides by copper(I) fluoride complexes

    KAUST Repository

    Liu, Yanpin

    2013-11-11

    Copper(I) fluoride complexes ligated by phenanthroline derivatives have been synthesized and structurally characterized by X-ray crystallography. These complexes adopt as either ionic or neutral forms in the solid state, depending on the steric bulkiness of the substituent groups on the phenanthroline ligands. These complexes react with primary and secondary alkyl bromides to produce the corresponding alkyl fluorides in modest to good yields. This new method is compatible with a variety of important functional groups such as ether, thioether, amide, nitrile, methoxyl, hydroxyl, ketone, ester, and heterocycle moieties. © 2013 American Chemical Society.

  9. Synthesis of New 3-(2-Chloroquinolin-3-yl)-5-Phenylisoxazole Derivatives via Click-Chemistry Approach

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Galleguillos, Carlos; Saavedra, Luis A.; Gutierrez, Margarita [Laboratorio de Sintesis Organica, Instituto de Quimica de Recursos Naturales, Universidad de Talca (Chile)

    2014-02-15

    Herein, we report the synthesis of new substituted 3-(2-chloroquinolin-3-yl)-5-phenylisoxazole (3a-j) by click chemistry in good to moderate yields. This approach is based on the regioselective copper(I)-catalyzed cycloaddition between different nitrile oxides derived from 2-chloroquinoline- 3-carbaldehyde (2a-j) and phenylacetylene. Finally these derivatives were screened for their antibacterial evaluation in vitro against three Gram-negative clinical bacteria: Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii using standard methods. (author)

  10. Methyltrioxorhenium as catalyst for olefin metathesis

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, W.A. (Technische Univ. Muenchen, Garching (Germany). Anorganisch-Chemisches Inst.); Wagner, W. (Consortium fuer Elektrochemische Industrie GmbH, Muenchen (Germany)); Flessner, U.N.; Volkhardt, U.; Komber, H. (Institut fuer Technologie der Polymere, Dresden (Germany))

    1991-12-01

    No cocatalysts are needed as additives when methyltrioxorhenium (MTO) supported on acidic carriers is employed to catalyze the metathesis of functionalized olefins. A typical system is MTO/Al{sub 2}O{sub 3}-SiO{sub 2}, which is active, for instance, in the metathesis of allyl halides, allylsilanes, unsaturated carboxylates, and nitriles. MTO in combination with R{sub n}AlCl{sub 3-n} is a homogeneous catalyst in ring-opening polymerizations (R = CH{sub 3}, C{sub 2}H{sub 5}; n = 1,2). (orig.).

  11. Structure-selectivity relationship in the cleavage of spirocyclopropyl oxindoles: An experimental and theoretical investigation

    Science.gov (United States)

    García-Vázquez, J. Benjamín; Bañuelos-Hernández, Angel E.; Trujillo-Serrato, Joel J.; Suárez-Castillo, Oscar R.; Ariza-Castolo, Armando; Morales-Ríos, Martha S.

    2017-10-01

    Heterogeneous catalytic hydrogenation of strained nitrile substituted spirocyclopropyl oxindoles in acetic anhydride, allowed to the regioselective formation of ring-opened 2-oxohomotryptamines accompanied by the ring-retained spirocyclopropyl acetamides as by products. The C3sbnd C9 bond fission would be induced by H atom attack via the plausible intermediacy of a stabilized benzolactam carbon-centered radical. The substituent effects on the stability of such radicals were analyzed in terms of the energy of SOMO orbitals, showing good agreement with σm Hammett constants. The theoretical results reflect experimental findings on the reactivity of the analyzed compounds.

  12. Rocket motors incorporating basalt fiber and nanoclay compositions and methods of insulating a rocket motor with the same

    Science.gov (United States)

    Gajiwala, Himansu M. (Inventor)

    2011-01-01

    An insulation composition that comprises at least one nitrile butadiene rubber, basalt fibers, and nanoclay is disclosed. Further disclosed is an insulation composition that comprises polybenzimidazole fibers, basalt fibers, and nanoclay. The basalt fibers may be present in the insulation compositions in a range of from approximately 1% by weight to approximately 6% by weight of the total weight of the insulation composition. The nanoclay may be present in the insulation compositions in a range of from approximately 5% by weight to approximately 10% by weight of the total weight of the insulation composition. Rocket motors including the insulation compositions and methods of insulating a rocket motor are also disclosed.

  13. Basalt fiber and nanoclay compositions, articles incorporating the same, and methods of insulating a rocket motor with the same

    Science.gov (United States)

    Gajiwala, Himansu M. (Inventor)

    2010-01-01

    An insulation composition that comprises at least one nitrile butadiene rubber, basalt fibers, and nanoclay is disclosed. Further disclosed is an insulation composition that comprises polybenzimidazole fibers, basalt fibers, and nanoclay. The basalt fibers may be present in the insulation compositions in a range of from approximately 1% by weight to approximately 6% by weight of the total weight of the insulation composition. The nanoclay may be present in the insulation compositions in a range of from approximately 5% by weight to approximately 10% by weight of the total weight of the insulation composition. Rocket motors including the insulation compositions and methods of insulating a rocket motor are also disclosed.

  14. Fungal His-tagged nitrilase from Gibberella intermedia: gene cloning, heterologous expression and biochemical properties.

    Directory of Open Access Journals (Sweden)

    Jin-Song Gong

    Full Text Available BACKGROUND: Nitrilase is an important member of the nitrilase superfamiliy. It has attracted substantial interest from academia and industry for its function of converting nitriles directly into the corresponding carboxylic acids in recent years. Thus nitrilase has played a crucial role in production of commercial carboxylic acids in chemical industry and detoxification of nitrile-contaminated wastes. However, conventional studies mainly focused on the bacterial nitrilase and the potential of fungal nitrilase has been far from being fully explored. Research on fungal nitrilase gene expression will advance our understanding for its biological function of fungal nitrilase in nitrile hydrolysis. METHODOLOGY/PRINCIPAL FINDINGS: A fungal nitrilase gene from Gibberella intermedia was cloned through reverse transcription-PCR. The open reading frame consisted of 963 bp and potentially encoded a protein of 320 amino acid residues with a theoretical molecular mass of 35.94 kDa. Furthermore, the catalytic triad (Glu-45, Lys-127, and Cys-162 was proposed and confirmed by site-directed mutagenesis. The encoding gene was expressed in Escherichia coli Rosetta-gami (DE3 and the recombinant protein with His(6-tag was purified to electrophoretic homogeneity. The purified enzyme exhibited optimal activity at 45°C and pH 7.8. This nitrilase was specific towards aliphatic and aromatic nitriles. The kinetic parameters V(max and K(m for 3-cyanopyridine were determined to be 0.81 µmol/min·mg and 12.11 mM through Hanes-Woolf plot, respectively. 3-Cyanopyridine (100 mM could be thoroughly hydrolyzed into nicotinic acid within 10 min using the recombinant strain with the release of about 3% nicotinamide and no substrate was detected. CONCLUSIONS/SIGNIFICANCE: In the present study, a fungal nitrilase was cloned from the cDNA sequence of G. intermedia and successfully expressed in E. coli Rosetta-gami (DE3. The recombinant strain displayed good 3-cyanopyridine

  15. An efficient and scalable one-pot double Michael addition-Dieckmann condensation for the synthesis of 4,4-disubstituted cyclohexane beta-keto esters.

    Science.gov (United States)

    DeGraffenreid, Michael R; Bennett, Sarah; Caille, Sebastien; Gonzalez-Lopez de Turiso, Felix; Hungate, Randall W; Julian, Lisa D; Kaizerman, Jacob A; McMinn, Dustin L; Rew, Yosup; Sun, Daqing; Yan, Xuelei; Powers, Jay P

    2007-09-14

    A simple, scalable, and efficient one-pot methodology for the synthesis of 4,4-disubstituted cyclohexane beta-keto esters from benzylic nitriles or esters and methyl acrylate promoted by potassium tert-butoxide is described. The process relies on a tandem double Michael addition-Dieckmann condensation reaction, which results in the formation of three discrete carbon-carbon bonds in a single pot, including a quaternary center. The method allows for the convenient and rapid synthesis of a variety of 4-aryl-4-cyano-2-carbomethoxycyclohexanone and 4-aryl-2,4-biscarbomethoxycyclohexanone building blocks for use in natural products synthesis and medicinal chemistry.

  16. Organobase-catalyzed three-component reactions for the synthesis of 4H-2-aminopyrans, condensed pyrans and polysubstituted benzenes

    OpenAIRE

    Moustafa Sherief Moustafa; Saleh Mohammed Al-Mousawi; Maghraby Ali Selim; Ahmed Mohamed Mosallam; Mohamed Hilmy Elnagdi

    2014-01-01

    Novel routes for the preparation of 2-amino-4H-pyran-3-carbonitrile 9, amino-arylbenzoic acid ester derivatives 13a,b, 2-aminotetrahydro-4H-chromene-3-carbonitrile 18, 3-amino-4-cyanotetrahydronaphthalene-2-carboxylic acid ester 26 and 4-amino-3,5-dicyanophthalic acid ester derivatives 37a–c were developed. The synthetic methods utilize one-pot reactions of acetylene carboxylic acid esters, α,β-unsaturated nitriles and/or active methylenenitriles in the presence of L-proline or DABCO. Plausib...

  17. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  18. Synthesis of D-fructose-derived spirocyclic 2-substituted-2-oxazoline ribosides

    Directory of Open Access Journals (Sweden)

    Madhuri Vangala

    2015-11-01

    Full Text Available The TMSOTf-mediated synthesis of β-configured spirocyclic 2-substituted-2-oxazoline ribosides was achieved using a “Ritter-like” reaction in toluene through nucleophilic addition of electron-rich nitriles to the oxacarbenium ion intermediate of 1,2;3,4-di-O-isopropylidene-β-D-psicofuranose derivatives with concomitant intramolecular trapping of the C2 hydroxymethyl group on the electrophilic nitrilium carbon. These carbohydrate-derived spirooxazolines are stable and were obtained in good yield with high stereoselectivity due to the conformational rigidity imparted by the 3,4-isopropylidene group.

  19. N-Heterocyclic Carbene-Catalysed Diastereoselective Vinylogous Michael Addition Reaction of gamma-Substituted deconjugated Butenolides

    KAUST Repository

    Guo, Hao

    2015-11-16

    An efficient N-heterocyclic carbene (NHC)-catalysed vinylogous Michael addition of deconjugated butenolides was developed. In the presence of 5 mol% of the NHC catalyst, both γ-alkyl and aryl-substituted deconjugated butenolides undergo vinylogous Michael addition with various α, β-unsaturated ketones, esters, or nitriles to afford γ,γ-disubstituted butenolides containing adjacent quaternary and tertiary carbon centers in good to excellent yields with excellent diastereoselectivities. In this process, the free carbene is assumed to act as a strong Brønsted base to promote the conjugate addition.

  20. Chemistry of di- and tetrahydropyrans. Communication 5. Ritter reactions in the pyran series

    Energy Technology Data Exchange (ETDEWEB)

    Ibatullin, U.G.; Mukhametova, D.Ya.; Makaeva, R.M.; Safarov, M.G.; Tolstikov, G.A.

    1986-08-20

    Reaction of 4-methylenetetra- and 4-methyl-5,6-dihydropyrans with aceto-, benzo-, and acrylonitriles under the conditions of the Ritter reaction leads to the formation of 4-acetylamino-4-methyltetrahydropyran in 45-65% yield. Since protonation of isomeric mixtures of substituted 5,6-, 3,6-dihydro-, and 4-methylenetetrahydropyrans generates the same intermediate carbenium ions, reaction of either of these materials with nitriles in conc. H/sub 2/SO/sub 4/ leads to the same amides in the heterocyclic series.

  1. An α-diaminoboryl carbanion assisted stereoselective single-pot preparation of α,β-disubstituted acrylonitriles.

    Science.gov (United States)

    Tomioka, Takashi; Sankranti, Rambabu; Vaughan, Trey G; Maejima, Toshihide; Yanase, Takayoshi

    2011-10-07

    An α-diaminoboryl carbanion-mediated one-pot olefination directly converts an acetonitrile or the homologous nitrile into a series of α,β-disubstituted acrylonitriles in a stereoselective manner. The protocol involves the formation of an α-substituted α-diaminoboryl acetonitrile and subsequent olefination with an aldehyde. The use of an aryl or conjugated aldehyde preferentially leads to a (Z)-acrylonitrile, while an aliphatic aldehyde gave an (E)-isomer as a major product. Two complementary approaches, a linear method and a divergent method, are developed.

  2. Determination of molybdenum in various materials by normal-phase liquid chromatography using N-benzoyl-N-phenylhydroxylamine

    Energy Technology Data Exchange (ETDEWEB)

    Bagur, Gracia; Sanchez-Vinas, Mercedes; Gazquez, Domingo [Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada (Spain)

    1995-06-20

    A normal-phase liquid chromatographic method for the selective determination of molybdenum with N-benzoyl-N-phenylhydroxylamine is described. The molybdenum(VI) complex was preconcentrated by extraction into chloroform and injected onto a nitrile column for chromatography. The mobile phase was a 0.075 M solution of reagent in chloroform (stabilized with amylene). The detection limit for molybdenum by the proposed method was 0.88 ng for a phase volume ratio of 20:1 (aqueous to organic). Molybdenum has been determined in several samples with satisfactory accuracy and precision.

  3. Bioenvironmental Engineer’s Guide to TVA-1000B Toxic Vapor Analyzer

    Science.gov (United States)

    2014-01-01

    Acetaldehyde 10.21 3-Butene nitrile 10.39 2-Chloro-2-methylpropane 10.61 Acetamide 9.77 Benzaldehyde 9.53 2-Chlorobutane 10.65 Acetic acid 10.69 Benzene...9.96 Propylene dichloride 10.87 V O Propylene imine 9.00 o-Vinyl toluene 8.20 Octane 9.82 Propylene oxide 10.22 Valeraldehyde 9.82 Oxygen 12.08...Propane 11.07 Thiophene 8.86 Propargyl alcohol 10.51 Toluene 8.82 Propiolactone 9.70 Tribromoethene 9.27 Propionaldehyde 9.98 Tribromofluoromethane

  4. Glove Testing for Performance Against Flying Glass Shards

    Science.gov (United States)

    2014-09-01

    Tested were the  HyFlex ® 11-518 polyurethane coated, Dyneema® glove by AnsellPro  HyFlex ® 11-435 polyurethane coated, Dyneema® glove by AnsellPro...gloves. Because of the laboratory environment that includes solvent use, nitrile gloves are worn over the protective gloves. The AnsellPro HyFlex ® 11...518 gloves and Memphis UltraTech® 9676 were considered the most dexterous of the gloves by the users. The thicker AnsellPro HyFlex ® 11-435 gloves

  5. Crystal structure of 2-benzylamino-4-(4-bromophenyl-6,7-dihydro-5H-cyclopenta[b]pyridine-3-carbonitrile

    Directory of Open Access Journals (Sweden)

    R. A. Nagalakshmi

    2015-03-01

    Full Text Available In the title compound C22H18BrN3, the cyclopentane ring adopts an envelope conformation with the central methylene C atom as the flap. The dihedral angles between the central pyridine ring and the pendant benzyl and and bromobenzene rings are 82.65 (1 and 47.23 (1°, respectively. In the crystal, inversion dimers linked by pairs of N—H...Nn (n = nitrile hydrogen bonds generate R22(12 loops. These dimers are linked by weak π–π interactions [centroid–centroid distance = 3.7713 (14 Å] into a layered structure.

  6. The usage of oil refining industry waste as vulcanization active ingredient of elastomeric composition

    OpenAIRE

    Kachkurkina, Iryna; Ovcharov, Valery; Schevchenko, Olena

    2009-01-01

    The influence of composite component perlite DPh-Zn, that is the waste of oil refining industry, on the formation of properties complex of rubber mixes and their vulcanizates on the basis of apolar cis-1,4-polyisoprene and butadiene-nitrile rubbers of various polarity has been investigated. It has been established that perlite DPh-Zn is the effective vulcanization active component of multifunctional action capable at 10.0 mass frac. concentration to replace in full or in part traditional acce...

  7. Viscoelastic properties of elastomeric materials for O-ring applications

    Science.gov (United States)

    Bower, Mark V.

    1989-01-01

    Redesign of the Space Shuttle Solid Rocket Booster necessitated re-evaluation of the material used in the field joint O-ring seals. This research project was established to determine the viscoelastic characteristics of five candidate materials. The five materials are: two fluorocarbon compounds, two nitrile compounds, and a silicon compound. The materials were tested in a uniaxial compression test to determine the characteristic relaxation functions. These tests were performed at five different temperatures. A master material curve was developed for each material from the experimental data. The results of this study are compared to tensile relaxation tests. Application of these results to the design analysis is discussed in detail.

  8. Microtropins A-I: 6'-O-(2″S,3″R)-2″-ethyl-2″,3″-dihydroxybutyrates of aliphatic alcohol β-D-glucopyranosides from the branches of Microtropis japonica.

    Science.gov (United States)

    Uemura, Yuka; Sugimoto, Sachiko; Matsunami, Katsuyoshi; Otsuka, Hideaki; Takeda, Yoshio; Kawahata, Masatoshi; Yamaguchi, Kentaro

    2013-03-01

    From the branches of Microtropis japonica (Celastraceae), nine aliphatic glucosides, named microtropins A-I, were isolated. The 6-position of glucose was esterified with (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid. Microtropins A-D contained a rare natured product nitrile functional group in their aglycones. The absolute structures of the (2S,3R)-2-ethyl-2,3-dihydroxybutyric acid moiety and aglycone of microtropin A were determined by an X-ray crystallographic method. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Density profiles of different negative ion mass groups at Titan as observed by Cassini's CAPS electron spectrometer

    Science.gov (United States)

    Wellbrock, A.; Coates, A. J.; Jones, G. H.; Waite, J. H.

    2013-12-01

    The discovery of heavy negative ions by Cassini's CAPS electron spectrometer (ELS) in Titan's ionosphere (Coates et al., 2007, Waite et al., 2007) suggests that complex hydrocarbon and nitrile processes occur in Titan's upper atmosphere which are also linked to haze formation. Negative ions are observed during Titan encounters at altitudes different mass groups as reported by Coates et al. (2007). These have been updated by Wellbrock et al. (2013) who performed a study investigating trends of mass groups with altitude using data from 34 negative ion encounters. We continue this work here by studying individual flybys in more detail. We investigate density profiles for different mass groups and total densities.

  10. SCALED-UP SYNTHESIS: SALTS OF CARFENTANIL AND REMIFENTANIL

    Science.gov (United States)

    2017-07-01

    nitrile into a methyl ester. Purification was affected by the precipitation of oxalate salt 3. No flash chromatography was performed over these three...of 6.67 M methanolic hydrogen chloride. The solution was stirred at room temperature for 18 h. Water (320 mL) was added, and the solution was...brown oil. This crude material was used without further purification . Compound 4: 1H NMR (CDCl3) δ 7.39–7.34 (m, 3H), 7.28–7.25 (m, 2H), 3.75 (s, 3H

  11. Synthesis and 1,3-Dipolar Cycloaddition Reactions of Chiral Maleimides

    Directory of Open Access Journals (Sweden)

    Lubor Fisera

    1997-02-01

    Full Text Available New routes to the synthesis of various novel chiral maleimides are described. The oxabicyclic anhydride 2 readily available exo-Diels-Alder adduct of furan and maleic anhydride was used as a vehicle, which in turn reacted with hydrochlorides of amino acids 3a-f in the presence of Et3N with release of furan to give the requisite novel chiral imides 4a-f in good to moderate yields. The stereoselectivity of 1,3-dipolar cycloaddition of nitrile oxides with prepared chiral imides 4a-f is investigated.

  12. Bis{N-[5-(4-methoxy?phen?yl)-1,3,4-oxa?diazol-2-yl]ethanimidamidato}copper(II)

    OpenAIRE

    Yacine Djebli; Salima Mosbah; Sihem Boufas; Leila Bencharif; Thierry Roisnel

    2010-01-01

    The title compound, [Cu(C11H11N4O2)2], was prepared by solvothermal synthesis using 2-amino-5-(4-methoxyphenyl)-1,3,4-oxadiazole and copper sulfate pentahydrate in an acetonitrile solution. The CuII atom lies on an inversion center and is four-coordinated in a slightly distorted square-planar geometry by four N atoms of the ligands obtained from the formation of a bond between the amine N atom of the oxadiazole molecule and the nitrile C atom of the solvent. In the crystal structure an interm...

  13. Regioselective Synthesis of Some Pyrazole Scaffolds Attached to Benzothiazole and Benzimidazole Moieties

    Directory of Open Access Journals (Sweden)

    Nabila A. Kheder

    2014-01-01

    Full Text Available Condensation of 2-(benzothiazol-2-ylacetonitrile (1 or 2-(1-methyl-1H-benzimidazol-2-ylacetonitrile (2 with thiophene-2-carbaldehyde afforded the corresponding acrylonitrile derivatives 3 or 4, respectively. The 1,3-dipolar cycloaddition reaction of the acrylonitrile 3 or 4 with nitrile-imine 6 gave novel pyrazole derivatives pendant to benzothiazole and benzimidazole. The pyrazoline derivative 7 was converted into the corresponding pyrazole derivative 11 via thermal elimination of hydrogen cyanide upon heating in sodium ethoxide solution. The structures of the synthesized products were confirmed by IR, 1H NMR, and mass spectral techniques.

  14. Bis{N-[5-(4-methoxyphenyl-1,3,4-oxadiazol-2-yl]ethanimidamidato}copper(II

    Directory of Open Access Journals (Sweden)

    Yacine Djebli

    2010-04-01

    Full Text Available The title compound, [Cu(C11H11N4O22], was prepared by solvothermal synthesis using 2-amino-5-(4-methoxyphenyl-1,3,4-oxadiazole and copper sulfate pentahydrate in an acetonitrile solution. The CuII atom lies on an inversion center and is four-coordinated in a slightly distorted square-planar geometry by four N atoms of the ligands obtained from the formation of a bond between the amine N atom of the oxadiazole molecule and the nitrile C atom of the solvent. In the crystal structure an intermolecular N—H...N hydrogen bond links inversion-related molecules.

  15. For ASTM F-08: Protective Capacity of Ice Hockey Player Helmets against Puck Impacts

    OpenAIRE

    Rousseau, Philippe; Hoshizaki, Thomas Blaine; Gilchrist, M. D.

    2014-01-01

    Many studies have assessed the ability of hockey helmets to protect against falls and collisions, yet none have addressed the injury risk associated with puck impacts. Thus, the purpose of this study was to document the capacity of a typical vinyl nitrile ice hockey helmet to reduce head accelerations and brain deformation caused by a puck impact. A bare and a helmeted Hybrid III male 50th percentile headform was struck with a puck three times to the forehead at 17, 23, 29, 35, and 41 m/s usi...

  16. Hydrogen Bonding and Vibrational Spectroscopy: A Theoretical Study

    Science.gov (United States)

    Chaban, Galina M.

    2005-01-01

    Effects of hydrogen bonding on vibrational spectra are studied for several hydrogen-bonded complexes, in which hydrogen bonding ranges from weak (25 kcal/mol). The systems studied include complexes of inorganic acids and salts with water and ammonia, as well as complexes of several organic molecules (nitriles and amino acids) with water. Since anharmonic effects are very strong in hydrogen-bonded systems, anharmonic vibrational frequencies and infrared intensities are computed using the correlation-corrected vibrational self-consistent field (CC-VSCF) method with ab initio potential surfaces at the MP2 and CCSD(T) levels. The most common spectral effects induced by hydrogen bonding are red shifts of stretching vibrational frequencies ranging from approx.200/cm to over 2000/cm and significant increases of infrared intensities for those bonds that participate in hydrogen bonding. However, some systems (e.g. nitrile-water complexes) exhibit shifts in the opposite direction (to the blue) upon formation of hydrogen bonds.

  17. UV–Vis Light-induced Aging of Titan’s Haze and Ice

    Science.gov (United States)

    Couturier-Tamburelli, Isabelle; Piétri, Nathalie; Le Letty, Vincent; Chiavassa, Thierry; Gudipati, Murthy

    2018-01-01

    The study of the photochemical aging of aerosols is an important tool for understanding Titan’s stratosphere/troposphere composition and evolution, particularly the haze. Laboratory simulations of the photoreactivity of the haze aerosol analogs provide insight into the photochemical evolution of Titan’s atmosphere at and below the haze layers. Here we use experimental simulations to investigate the evolution of the laboratory analogs of these organic aerosols under ultraviolet (UV)–visible (Vis) photons, which make it through the haze layers during their sedimentation process. We present experimental results for the aging of Titan’s aerosol analogs obtained from two dominant nitrogen-containing organics, HC3N and HCN, under simulated Titan atmospheric conditions (photons and temperature). We report that volatile nitriles condensed on haze particles could be incorporated through photochemistry and provide one such sink mechanism for nitrile compounds. We provide laboratory evidence that the organic aerosols could photochemically evolve during their sedimentation through Titan’s atmosphere.

  18. Standardization of skin cleansing in vivo: part I. Development of an Automated Cleansing Device (ACiD).

    Science.gov (United States)

    Sonsmann, F K; Strunk, M; Gediga, K; John, C; Schliemann, S; Seyfarth, F; Elsner, P; Diepgen, T L; Kutz, G; John, S M

    2014-05-01

    To date, there are no legally binding requirements concerning product testing in cosmetics. This leads to various manufacturer-specific test methods and absent transparent information on skin cleansing products. A standardized in vivo test procedure for assessment of cleansing efficacy and corresponding barrier impairment by the cleaning process is needed, especially in the occupational context where repeated hand washing procedures may be performed at short intervals. For the standardization of the cleansing procedure, an Automated Cleansing Device (ACiD) was designed and evaluated. Different smooth washing surfaces of the equipment for ACiD (incl. goat hair, felt, felt covered with nitrile caps) were evaluated regarding their skin compatibility. ACiD allows an automated, fully standardized skin washing procedure. Felt covered with nitrile as washing surface of the rotating washing units leads to a homogenous cleansing result and does not cause detectable skin irritation, neither clinically nor as assessed by skin bioengineering methods (transepidermal water loss, chromametry). Automated Cleansing Device may be useful for standardized evaluation of the cleansing effectiveness and parallel assessment of the corresponding irritancy potential of industrial skin cleansers. This will allow objectifying efficacy and safety of industrial skin cleansers, thus enabling market transparency and facilitating rational choice of products. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Molecular and system parameters governing mass and charge transport in polar liquids and electrolytes.

    Science.gov (United States)

    Petrowsky, Matt; Fleshman, Allison; Ismail, Mohd; Glatzhofer, Daniel T; Bopege, Dharshani N; Frech, Roger

    2012-08-23

    Onsager's model of the dielectric constant is used to provide a molecular-level picture of how the dielectric constant affects mass and charge transport in organic liquids and organic liquid electrolytes. Specifically, the molecular and system parameters governing transport are the molecular dipole moment μ and the solvent dipole density N. The compensated Arrhenius formalism (CAF) writes the temperature-dependent ionic conductivity or diffusion coefficient as an Arrhenius-like expression that also includes a static dielectric constant (ε(s)) dependence in the exponential prefactor. The temperature dependence of ε(s) and therefore the temperature dependence of the exponential prefactor is due to the quantity N/T, where T is the temperature. Using the procedure described in the CAF, values of the activation energy can be obtained by scaling out the N/T dependence instead of the ε(s) dependence. It has been previously shown that a plot of the prefactors versus ε(s) results in a master curve, and here it is shown that a master curve also results by plotting the prefactors against N/T. Therefore, the CAF can be applied by using temperature-dependent density data instead of temperature-dependent dielectric constant data. This application is demonstrated for diffusion data of n-nitriles, n-thiols, n-acetates, and 2-ketones, as well as conductivity data for dilute tetrabutylammonium triflate-nitrile electrolytes.

  20. Stimuli-responsive cement-reinforced rubber.

    Science.gov (United States)

    Musso, Simone; Robisson, Agathe; Maheshwar, Sudeep; Ulm, Franz-Josef

    2014-05-14

    In this work, we report the successful development of a cement-rubber reactive composite with reversible mechanical properties. Initially, the composite behaves like rubber containing inert filler, but when exposed to water, it increases in volume and reaches a stiffness that is intermediate between that of hydrogenated nitrile butadiene rubber (HNBR) and hydrated cement, while maintaining a relatively large ductility characteristic of rubber. After drying, the modulus increases even further up to 400 MPa. Wet/drying cycles prove that the elastic modulus can reversibly change between 150 and 400 MPa. Utilizing attenuated total reflection Fourier transform infrared spectroscopy), we demonstrate that the high pH produced by the hydration of cement triggers the hydrolysis of the rubber nitrile groups into carboxylate anions. Thus, the salt bridges, generated between the carboxylate anions of the elastomer and the cations of the filler, are responsible for the reversible variations in volume and elastic modulus of the composite as a consequence of environmental moisture exposure. These results reveal that cement nanoparticles can successfully be used to accomplish a twofold task: (a) achieve an original postpolymerization modification that allows one to work with carboxylate HNBR (HXNBR) not obtained by direct copolymerization of carboxylate monomers with butadiene, and (b) synthesize a stimuli-responsive polymeric composite. This new type of material, having an ideal behavior for sealing application, could be used as an alternative to cement for oil field zonal isolation applications.

  1. Radiation vulcanization of rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-02-01

    An abstract of the radiation process of polymer materials and the polymer reaction by radiation is explained. Main radiation is 250 keV to 10 MeV of electron rays in the industry. Radiation cross-linked rubber has less the tensile strength than that by sulfur and organic peroxide crosslinking. The main origins of low tensile strength are caused by cut of backbone chain and ozone depend on radiation. Acceleration of crosslinking and short time of radiation are necessary to improve these defects. To accelerate crosslinking, we used crosslinking accelerators, for example, three poly-functional monomers (PFM). The maximum tensile strength of styrene-butadiene rubber (SBR) not added crosslinking accelerators showed 3 MPa at 110 kGy, but SBR added A-TMMT (tetramethylolmethane tetraacrylate) showed 5.5 MPa at 110 kGy. Radiation crosslinking of many kinds of rubber: isoprene (IR), SBR, CR, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), butyl rubber (IIR), chlorinated butyl rubber (CIIR), EPM and TPE are explained. (S.Y.)

  2. N-nitro-L-arginine, a nitric oxide synthase inhibitor, aggravates iminodipropionitrile-induced neurobehavioral and vestibular toxicities in rats.

    Science.gov (United States)

    Khan, Haseeb Ahmad

    2012-11-01

    Exposure of iminodipropionitrile (IDPN) to rodents produces permanent behavioral syndrome characterized by repetitive head movements, circling and back walking. Other synthetic nitriles of industrial importance such as crotonitrile and allylnitrile are also able to produce similar motor deficits in experimental animals. However, due to the well-defined behavioral deficits and their easy quantification, IDPN-induced behavioral syndrome is a preferential animal model to test the interaction of various agents with synthetic nitriles. This study reports the effect of non-specific nitric oxide synthase inhibitor, N-nitro-L-arginine (NARG) on IDPN-induced neurobehavioral toxicity in adult male Wistar rats. Four groups of animals were given i.p. injections of IDPN (100 mg/kg) for 6 days. These rats were treated with oral administration of NARG in the doses of 0 (IDPN alone group), 50, 150 and 300 mg/kg, 60 min before IDPN, respectively. Control rats received vehicle only, whereas another group was treated with 300 mg/kg of NARG alone (without IDPN). The results showed that NARG significantly exacerbated the incidence and intensity of IDPN-induced dyskinetic head movements, circling and back walking. The histology of inner ear showed massive degeneration of the sensory hair cells in the crista ampullaris of rats receiving the combined treatment with IDPN and NARG, suggesting a possible role of nitric oxide in IDPN-induced neurobehavioral syndrome in rats. Copyright © 2011 Elsevier GmbH. All rights reserved.

  3. Slip resistant properties of footwear on ice.

    Science.gov (United States)

    Gao, Chuansi; Abeysekera, John; Hirvonen, Mikko; Grönqvist, Raoul

    2004-05-15

    Current research on slipperiness of footwear has mainly focused on floors and lubricated floors. Slips and falls on icy and snowy surfaces involve not only outdoor workers, but also pedestrians and the general public; and occur in cold regions and in winter season in many parts of the world. However, in comparison with the size of the problem, research on slips and falls on icy and snowy surfaces has been scarce. The objective of this paper is to explore the slip resistant properties of footwear (soling materials, roughness and hardness) on ice. The coefficients of kinetic friction of four different soling materials (synthetic rubber, nitrile rubber, natural rubber and polyurethane) were measured on ice (-12 degrees C). The outsole roughness and hardness were also measured. Results showed that the polyurethane soling did not perform better than synthetic rubber, nitrile rubber and natural rubber on pure hard ice (-12 degrees C). Soling roughness was positively correlated with the coefficient of kinetic friction. The most slip resistant soling material (polyurethane) on floors and lubricated floors may not provide sufficient slip resistance on ice.

  4. Acrylate-induced allergic contact dermatitis in a car windscreen repairer.

    Science.gov (United States)

    Fremlin, G; Sansom, J

    2014-10-01

    We report a case of an allergic skin reaction to ultraviolet-cured acrylates in a windscreen repair worker. The patient presented with a 6 month history of fingertip dryness, vesicles and desquamation. He had worked as a self-employed car windscreen repairer for 19 years. Previous management with vinyl glove protection and treatment with clobetasol propionate ointment had produced little improvement. He was patch tested to the British Society for Cutaneous Allergy standard and preservatives series and to the two acrylates used in his work environment, identified using safety data sheets, methyl methacrylate 2% pet and 2-hydroxyethylmethacrylate (2-HEMA) 2% pet. A positive reaction was seen at Day 4 to 2-HEMA, but all other patch tests were negative. An occupational allergic contact dermatitis to 2-HEMA was diagnosed. The patient was given avoidance advice and advised to use nitrile gloves. Although he was unable to give up his current work, he has continued his job using nitrile gloves with marked improvement. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. In vivo testing of the protection of gloves against acrylates in dentin-bonding systems on patients with known contact allergy to acrylates.

    Science.gov (United States)

    Andersson, T; Bruze, M; Björkner, B

    1999-11-01

    Occupational contact allergies to dental acrylates are increasing. Commonly used gloves protect poorly against acrylates. The protective efficacy in vivo of other, newer glove materials is not fully known. In this study, an open chamber system was used for testing the protection in vivo of 6 different gloves (1 vinyl glove, 2 latex gloves, 2 nitrile gloves and the 4H glove) against a commonly used dental adhesive, Scotchbond 1, containing 2-hydroxyethyl methacrylate (2-HEMA) and triethylene glycol dimethacrylate (TREGDMA). 8 patients with known contact allergy to 2-HEMA participated. Provocation with 50 microl of the adhesive for 7.5, 15 and 30 min was performed for each glove. The test demonstrated clear differences in the protective efficacy between the gloves. The 4H glove gave by far the best protection, followed by one of the nitrile gloves. One of the latex gloves and the vinyl glove gave a very poor protection against the adhesive. A dose-response relationship was observed between different application times of the acrylate product. The test model promises to be a useful clinical complement to in vitro methods in individual preventive measures against contact sensitization to acrylates.

  6. In situ FT-IR investigation of etravirine speciation in pores of SBA-15 ordered mesoporous silica material upon contact with water.

    Science.gov (United States)

    Mellaerts, Randy; Fayad, Elie J; Van den Mooter, Guy; Augustijns, Patrick; Rivallan, Mickaël; Thibault-Starzyk, Frédéric; Martens, Johan A

    2013-02-04

    Ordered mesoporous silica (OMS) has been recognized as promising adsorbent material for drug molecules with low aqueous solubility. The release of drug molecules from OMS upon contact with aqueous environment enhances their oral bioavailability. The release is governed by a complex interplay of adsorption, diffusion, and intermolecular interaction inside OMS pores. The presence of water hampers in situ FT-IR investigation of the behavior of the drug molecules upon release. The poorly water-soluble etravirine molecule having two nitrile functions was selected for an in situ FT-IR spectroscopic investigation of the release process. The stretching vibration of the nitrile organic function (υ(CN)) is a spectral feature that is accessible to FT-IR even in the presence of water. Etravirine depending on the loading was found to be present in SBA-15 pores as isolated adsorbed molecules, solvated molecules, and aggregates with intermolecular interaction similar to the crystalline state, each with a different spectroscopic fingerprint. Etravirine evacuation from the SBA-15 pores was shown to proceed in the solvated state. Surprisingly, the etravirine clusters inside pores were converted more readily into solvated molecules compared to individually adsorbed molecules.

  7. Copoly(arlene ether)s containing pendant sulfonic acid groups as proton exchange membrane

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung [Los Alamos National Laboratory; Kim, Dae Sik [CANADA NRC; Robertson, Gilles [CANADA NRC; Guiver, Michael [CANADA NRC

    2008-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The P AE and PAEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2-phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. The sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sP AE and sP AEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (DS) of 1.0 had high ion exchange capacities (IEC{sub v}(wet) (volume-based, wet state)) of 1.77 and 2.55 meq./cm{sup 3}, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5-51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the area of outstanding properties in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based). Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  8. Researches on increasing compatibility between mixtures of PPS (poly-phenylene sulfide) and polyamide; Recherches en vue de la compatibilisation de melanges de polyamide et de polysulfure de phenylene

    Energy Technology Data Exchange (ETDEWEB)

    Montagne, O.

    1997-01-08

    This work aims to increase the compatibility between PPS (Poly Phenylene Sulfide) and a Polyamide. In order to do so, a bloc co-polymer was synthesised by the coupling of telechelic oligomers of PPS and PA oligomers. These telechelic oligomers of PPS were synthesised in a single step which a synthesis was made possible were the nitrile and secondary amide functions. These oligomers were characterised by various techniques which lead to a rather good precision (difficult to achieve for insolubility reasons). These oligomers were then coupled with the polyamide oligomers. In order to do so, a new reaction was discovered between an aromatic nitrile and a secondary aliphatic amide. It was assessed both on model molecules and on oligomers. An original mechanism is proposed. Once the characterisation of these copolymers was made, various blends of PPS and PA were studied. At last, the incorporation of the block copolymers in the blend obtained by a twin screw extruder, lead to an improvement of the compatibility between the two polymers and in an increase of the resistance to crack propagation. (author) 314 refs.

  9. Preparation of Amidoxime Polyacrylonitrile Chelating Nanofibers and Their Application for Adsorption of Metal Ions

    Directory of Open Access Journals (Sweden)

    You-Lo Hsieh

    2013-03-01

    Full Text Available Polyacrylonitrile (PAN nanofibers were prepared by electrospinning and they were modified with hydroxylamine to synthesize amidoxime polyacrylonitrile (AOPAN chelating nanofibers, which were applied to adsorb copper and iron ions. The conversion of the nitrile group in PAN was calculated by the gravimetric method. The structure and surface morphology of the AOPAN nanofiber were characterized by a Fourier transform infrared spectrometer (FT-IR and a scanning electron microscope (SEM, respectively. The adsorption abilities of Cu2+ and Fe3+ ions onto the AOPAN nanofiber mats were evaluated. FT-IR spectra showed nitrile groups in the PAN were partly converted into amidoxime groups. SEM examination demonstrated that there were no serious cracks or sign of degradation on the surface of the PAN nanofibers after chemical modification. The adsorption capacities of both copper and iron ions onto the AOPAN nanofiber mats were higher than those into the raw PAN nanofiber mats. The adsorption data of Cu2+ and Fe3+ ions fitted particularly well with the Langmuir isotherm. The maximal adsorption capacities of Cu2+ and Fe3+ ions were 215.18 and 221.37 mg/g, respectively.

  10. Structural and spectroscopic analysis of the kinase inhibitor bosutinib and an isomer of bosutinib binding to the Abl tyrosine kinase domain.

    Directory of Open Access Journals (Sweden)

    Nicholas M Levinson

    Full Text Available Chronic myeloid leukemia (CML is caused by the kinase activity of the BCR-Abl fusion protein. The Abl inhibitors imatinib, nilotinib and dasatinib are currently used to treat CML, but resistance to these inhibitors is a significant clinical problem. The kinase inhibitor bosutinib has shown efficacy in clinical trials for imatinib-resistant CML, but its binding mode is unknown. We present the 2.4 Å structure of bosutinib bound to the kinase domain of Abl, which explains the inhibitor's activity against several imatinib-resistant mutants, and reveals that similar inhibitors that lack a nitrile moiety could be effective against the common T315I mutant. We also report that two distinct chemical compounds are currently being sold under the name "bosutinib", and report spectroscopic and structural characterizations of both. We show that the fluorescence properties of these compounds allow inhibitor binding to be measured quantitatively, and that the infrared absorption of the nitrile group reveals a different electrostatic environment in the conserved ATP-binding sites of Abl and Src kinases. Exploiting such differences could lead to inhibitors with improved selectivity.

  11. Structural and spectroscopic analysis of the kinase inhibitor bosutinib and an isomer of bosutinib binding to the Abl tyrosine kinase domain.

    Science.gov (United States)

    Levinson, Nicholas M; Boxer, Steven G

    2012-01-01

    Chronic myeloid leukemia (CML) is caused by the kinase activity of the BCR-Abl fusion protein. The Abl inhibitors imatinib, nilotinib and dasatinib are currently used to treat CML, but resistance to these inhibitors is a significant clinical problem. The kinase inhibitor bosutinib has shown efficacy in clinical trials for imatinib-resistant CML, but its binding mode is unknown. We present the 2.4 Å structure of bosutinib bound to the kinase domain of Abl, which explains the inhibitor's activity against several imatinib-resistant mutants, and reveals that similar inhibitors that lack a nitrile moiety could be effective against the common T315I mutant. We also report that two distinct chemical compounds are currently being sold under the name "bosutinib", and report spectroscopic and structural characterizations of both. We show that the fluorescence properties of these compounds allow inhibitor binding to be measured quantitatively, and that the infrared absorption of the nitrile group reveals a different electrostatic environment in the conserved ATP-binding sites of Abl and Src kinases. Exploiting such differences could lead to inhibitors with improved selectivity.

  12. Crystal structures of 4-chloropyridine-2-carbonitrile and 6-chloropyridine-2-carbonitrile exhibit different intermolecular π-stacking, C—H...Nnitrile and C—H...Npyridine interactions

    Directory of Open Access Journals (Sweden)

    Matthew J. Montgomery

    2015-07-01

    Full Text Available The two title compounds are isomers of C6H3ClN2 containing a pyridine ring, a nitrile group, and a chloro substituent. The molecules of each compound pack together in the solid state with offset face-to-face π-stacking, and intermolecular C—H...Nnitrile and C—H...Npyridine interactions. 4-Chloropyridine-2-carbonitrile, (I, exhibits pairwise centrosymmetric head-to-head C—H...Nnitrile and C—H...Npyridine interactions, forming one-dimensional chains, which are π-stacked in an offset face-to-face fashion. The intermolecular packing of the isomeric 6-chloropyridine-2-carbonitrile, (II, which differs only in the position of the chloro substituent on the pyridine ring, exhibits head-to-tail C—H...Nnitrile and C—H...Npyridine interactions, forming two-dimensional sheets which are π-stacked in an offset face-to-face fashion. In contrast to (I, the offset face-to-face π-stacking in (II is formed between molecules with alternating orientations of the chloro and nitrile substituents.

  13. Ionic Borate-Based Covalent Organic Frameworks: Lightweight Porous Materials for Lithium-Stable Solid State Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Black, Hayden T; Harrison, Katharine Lee

    2016-10-01

    The synthesis and characterization of the first polyelectrolyte of intrinsic microporosity (PEIM) is described. The novel material was synthesized via reaction between the nitrile group in the polymer backbone and n-butyl lithium, effectively anchoring an imine anion to the porous framework while introducing a mobile lithium counterion. The PEIM was characterized by 13C, 1H, and 7Li NMR experiments, revealing quantitative conversion of the nitrile functionality to the anionic imine. Variable temperature 7Li NMR analysis of the dry PEIM and the electrolyteswollen PEIM revealed that lithium ion transport within the dry PEIM was largely due to interchain hopping of the Li+ ions, and that the mobility of polymer associated Li+ was reduced after swelling in electrolyte solution. Meanwhile, the swollen PEIM supported efficient transport of dissolved Li+ within the expanded pores. These results are discussed in the context of developing novel solid or solid-like lithium ion electrolytes using the new PEIM material.

  14. The full-scale process and design changes for elimination of insulation edge separations and voids in tang flap area

    Science.gov (United States)

    Danforth, Richard A.

    1991-01-01

    Qualification of the full-scale process and design changes for elimination of redesigned solid rocket motor tang nitrile butadiene rubber insulation edge separations and voids was performed from 24 March to 3 December 1990. The objectives of this test were: to qualify design and process changes on flight hardware using a tie ply between the redesigned solid rocket motor steel case and the nitrile butadiene rubber insulation over the tang capture features; to qualify the use of methyl ethyl ketone in the tang flap region to reduce voids; and to determine if holes in the separator film reduce voids in the tang flap region. The tie ply is intended to aid insulation flow during the insulation cure process, and thus reduce or eliminate edge unbonds. Methyl ethyl ketone is intended to reduce voids in the tang flap area by providing better tacking characteristics. The perforated film was intended to provide possible vertical breathe paths to reduce voids in the tang area. Tang tie ply testing consisted of 270 deg of the tang circumference using a new layup method and 90 deg of the tang circumference using the current layup methods. Tie ply process success was defined as a reduction of insulation unbonds. Lack of any insulation edge unbonds on the tang area where the new process was used, and the presence of 17 unbonds with the current process, proves the test to be a success. Successful completion of this test has qualified the new processes.

  15. An evaluation of the effect of various gloves on polymerization inhibition of elastomeric impression materials: An In vitro study

    Directory of Open Access Journals (Sweden)

    Vinuta Hiremath

    2017-01-01

    Full Text Available Background: Latex protective barriers such as gloves and rubber dam material have been used widely in restorative procedures for crown and bridge. However, the chemical used during latex glove fabrication is thought to inhibit the polymerization of elastomeric impression materials used for impression making which has a detrimental effect on the dimensional accuracy and surface definition of resultant casts used for restorative procedures. The objectives of the study were to examine the surface of different elastomeric impressions on contact with various gloves. Materials and Methods: This clinical study included a total of eighty specimens of two types of the putty elastomeric impression material were hand manipulated by wearing three different gloves materials and is placed on a marked area of a clean and alcohol-treated glass slab at room temperature. The specimens examined for any signs of polymerization inhibition. The specimen will be rated as being “inhibited” if any residue remains on the glass slab and absence of the above will result as “no inhibition.” Results: The results showed no interference with the polymerization inhibition of the selected elastomers followed by the nitrile glove. The latex gloves showed inhibited set of the elastomeric impression material but set after sometime confirming time-dependent inhibition of the impression material. Conclusion: This study shows that the use of latex and sometime nitrile gloves during crown and bridge procedures should be contraindicated and the use of vinyl gloves should be stressed when working with elastomeric impression materials.

  16. "Additive" cooperativity of hydrogen bonds in complexes of catechol with proton acceptors in the gas phase: FTIR spectroscopy and quantum chemical calculations.

    Science.gov (United States)

    Varfolomeev, Mikhail A; Klimovitskii, Alexander E; Abaidullina, Dilyara I; Madzhidov, Timur I; Solomonov, Boris N

    2012-06-01

    Experimental study of hydrogen bond cooperativity in hetero-complexes in the gas phase was carried out by IR-spectroscopy method. Stretching vibration frequencies of O-H groups in phenol and catechol molecules as well as of their complexes with nitriles and ethers were determined in the gas phase using a specially designed cell. O-H groups experimental frequency shifts in the complexes of catechol induced by the formation of intermolecular hydrogen bonds are significantly higher than in the complexes of phenol due to the hydrogen bond cooperativity. It was shown that the cooperativity factors of hydrogen bonds in the complexes of catechol with nitriles and ethers in the gas phase are approximately the same. Quantum chemical calculations of the studied systems have been performed using density functional theory (DFT) methods. It was shown, that theoretically obtained cooperativity factors of hydrogen bonds in the complexes of catechol with proton acceptors are in good agreement with experimental values. Cooperative effects lead to a strengthening of intermolecular hydrogen bonds in the complexes of catechol on about 30%, despite the significant difference in the proton acceptor ability of the bases. The analysis within quantum theory of atoms in molecules was carried out for the explanation of this fact. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. In-Situ Measurements of HCN and CH3CN In the Pacific Troposphere: Sources, Sinks, and Comparisons with Satellite Observations

    Science.gov (United States)

    Singh, Hanwant B.; Salas, L.; Herlth, D.; Viezee, W.; Jacob, D.; Blake, D.; Sachse, G.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    A new capillary gas chromatographic method using a Reduction Gas Detector was developed to measure HCN and CH3CN in the remote troposphere. This instrumental configuration was deployed for the very first time in the Trace-P field mission performed during the spring of 2001. The NASA DC-8 aircraft afforded an opportunity to measure HCN and CH3CN in polluted and pristine environments over the Pacific to a maximum altitude of 12 km. These are some of the first in situ measurements of the distribution of HCN and CH3CN over the Pacific. Large background concentrations of both nitriles were found to be present and significant variability was observed. The abundance of HCN and CH3CN was strongly impacted by outflow of pollution from Asia. In general there appeared to be a direct but nonlinear relationship between the mixing ratios of HCN and CH3CN. The vertical structure of these chemicals shows direct evidence of the presence of a significant oceanic sink. These observations will be compared with the column content HCN data from satellites and other available measurements. A large body of data have been collected and are being analyzed, both statistically and with the help of models, to better understand the sources and sinks of these nitriles. These results will be presented.

  18. Chemistry by nanocatalysis: First example of a solid-supported RAPTA complex for organic reactions in aqueous medium

    KAUST Repository

    García-Garrido, Sergio E.

    2010-11-18

    A ruthenium-arene-PTA (RAPTA) complex has been supported for the first time on an inorganic solid, that is, silica-coated ferrite nanoparticles. The resulting magnetic material proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentration, environmentally friendly water as a reaction medium, with no use at all of organic solvent during or after the reactions, and microwaves as an alternative energy source renders the synthetic processes reported herein "truly" green and sustainable. RAPTA\\'s delight: A nano-RAPTA complex supported on silica-coated ferrite nanoparticles proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentrations, water as a reaction medium, and microwaves as an energy source renders these processes green and sustainable. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Oriented growth of magnetite along the carbon nanotubes via covalently bonded method in a simple solvothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Zhan Yingqing; Zhao Rui; Meng Fanbing; Lei Yajie; Zhong Jiachun; Yang Xulin [Research Branch of Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); Liu Xiaobo, E-mail: liuxb@uestc.edu.cn [Research Branch of Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2011-06-15

    Highlights: > Novel CNTs/magnetite hybrid materials were prepared via covalently bonded method. > Stable interaction between nitriles and iron ion promoted the oriented growth of magnetite. > The hybrid material exhibited higher magnetism and electromagnetic properties - Abstract: A new type of CNTs/magnetite hybrid material was prepared via covalently bonded method in a simple solvothermal system using FeCl{sub 3} as iron source, ethylene glycol as the reducing agent, and 4-aminophenoxyphthalonitrile-grafted CNTs as templates. The magnetite nanoparticles, with the diameters of 70-80 nm, were self-assembled along the CNTs. The FTIR, UV-vis and DSC revealed that a stable covalent bond between nitriles group and iron ion promoted the oriented growth of magnetite nanoparticles along the CNTs, resulting in good dispersibility and solution storage stability. The magnetic properties measurements indicated that a higher saturated magnetization (70.7 emu g{sup -1}) existed in the CNTs/magnetite hybrid material, which further enhanced the electromagnetic properties. The magnetic loss was caused mainly by natural resonance, which is in good agreement with the Kittel equation results. The novel electromagnetic hybrid material is believed to have potential applications in the microwave absorbing performances.

  20. Isotopic Anomalies in Primitive Solar System Matter: Spin-State-Dependent Fractionation of Nitrogen and Deuterium in Interstellar Clouds

    Science.gov (United States)

    Wirstrom, Eva S.; Charnley, Steven B.; Cordiner, Martin A.; Milam, Stefanie N.

    2012-01-01

    Organic material found in meteorites and interplanetary dust particles is enriched in D and N-15. This is consistent with the idea that the functional groups carrying these isotopic anomalies, nitriles and amines, were formed by ion-molecule chemistry in the protosolar nebula, Theoretical models of interstellar fractionation at low temperatures predict large enrichments in both D and N-15 and can account for the largest isotopic enrichments measured in carbonaceous meteorites. However, more recent measurements have shown that, in some primitive samples, a large N-15 enrichment does not correlate with one in D, and that some D-enriched primitive material displays little, if any, N-15 enrichment. By considering the spin-state dependence in ion-molecule reactions involving the ortho and para forms of H2, we show that ammonia and related molecules can exhibit such a wide range of fractionation for both N-15 and D in dense cloud cores. We also show that while the nitriles, HCN and HNC, contain the greatest N=15 enrichment, this is not expected to correlate with extreme D enrichment. These calculations therefore support the view that solar system N-15 and D isotopic anomalies have an interstellar heritage. We also compare our results to existing astronomical observations and briefly discuss future tests of this model.